Test results - Codility

Tasks Details

easy

1. Nesting

Determine whether a given string of parentheses (single type) is properly nested.

Task Score

100%

Correctness

100%

Performance

100%

A string S consisting of N characters is called properly nested if:

S is empty;

S has the form "(U)" where U is a properly nested string;

S has the form "VW" where V and W are properly nested strings.

For example, string "(()(())())" is properly nested but string "())" isn't.

Write a function:

int solution(string &S);

that, given a string S consisting of N characters, returns 1 if string S is properly nested and 0 otherwise.

For example, given S = "(()(())())", the function should return 1 and given S = "())", the function should return 0, as explained above.

Write an efficient algorithm for the following assumptions:

N is an integer within the range [0..1,000,000];

string S is made only of the characters '(' and/or ')'.

Solution

Programming language used C++

Time spent on task 9 minutes

Notes

not defined yet

Task timeline

Code: 14:38:12 UTC, java, autosave

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1 2 3 4 5 6 7 8 9 10 11

// you can also use imports, for example:
// import java.util.*;

// you can write to stdout for debugging purposes, e.g.
// System.out.println("this is a debug message");

class Solution {
    public int solution(String S) {
        // write your code in Java SE 8
    }
}

Code: 14:38:31 UTC, cpp, autosave

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// you can use includes, for example:
#include <bits/stdc++.h>

// you can write to stdout for debugging purposes, e.g.
// cout << "this is a debug message" << endl;

int solution(string &S) {
    // write your code in C++14 (g++ 6.2.0)
    
}

Code: 14:38:50 UTC, cpp, autosave

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1 2 3 4 5 6 7 8 9 10 11 12

// you can use includes, for example:
#include <bits/stdc++.h>

// you can write to stdout for debugging purposes, e.g.
// cout << "this is a debug message" << endl;

int solution(string &S) {
    // write your code in C++14 (g++ 6.2.0)
    int len = S.length();
    
    for(int i=0)
}

Code: 14:39:06 UTC, cpp, autosave

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1 2 3 4 5 6 7 8 9 10 11 12 13 14

// you can use includes, for example:
#include <bits/stdc++.h>

// you can write to stdout for debugging purposes, e.g.
// cout << "this is a debug message" << endl;

int solution(string &S) {
    // write your code in C++14 (g++ 6.2.0)
    int len = S.length();

    for(int i=0; i<len; i++){
        
    }
}

Code: 14:39:16 UTC, cpp, autosave

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1 2 3 4 5 6 7 8 9 10 11 12 13 14

// you can use includes, for example:
#include <bits/stdc++.h>

// you can write to stdout for debugging purposes, e.g.
// cout << "this is a debug message" << endl;

int solution(string &S) {
    // write your code in C++14 (g++ 6.2.0)
    int len = S.length();

    for(int i=0; i<len; i++){
        S
    }
}

Code: 14:39:27 UTC, cpp, autosave

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1 2 3 4 5 6 7 8 9 10 11 12 13 14

// you can use includes, for example:
#include <bits/stdc++.h>

// you can write to stdout for debugging purposes, e.g.
// cout << "this is a debug message" << endl;

int solution(string &S) {
    // write your code in C++14 (g++ 6.2.0)
    int len = S.length();

    for(int i=0; i<len; i++){
        
    }
}

Code: 14:39:57 UTC, cpp, autosave

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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17

// you can use includes, for example:
#include <bits/stdc++.h>

// you can write to stdout for debugging purposes, e.g.
// cout << "this is a debug message" << endl;

int solution(string &S) {
    // write your code in C++14 (g++ 6.2.0)
    int len = S.length();
    int stack<int> st

    for(int i=0; i<len; i++){
        if(S[i] == '('){

        }
    }
}

Code: 14:40:11 UTC, cpp, autosave

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// you can use includes, for example:
#include <bits/stdc++.h>

// you can write to stdout for debugging purposes, e.g.
// cout << "this is a debug message" << endl;

int solution(string &S) {
    // write your code in C++14 (g++ 6.2.0)
    int len = S.length();
    stack<int> st;

    for(int i=0; i<len; i++){
        if(S[i] == '('){
            st.push()
        }
    }
}

Code: 14:40:26 UTC, cpp, autosave

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// you can use includes, for example:
#include <bits/stdc++.h>

// you can write to stdout for debugging purposes, e.g.
// cout << "this is a debug message" << endl;

int solution(string &S) {
    // write your code in C++14 (g++ 6.2.0)
    int len = S.length();
    stack<char> st;

    for(int i=0; i<len; i++){
        if(S[i] == '('){
            st.push('(');
        }
    }
}

Code: 14:40:40 UTC, cpp, autosave

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// you can use includes, for example:
#include <bits/stdc++.h>

// you can write to stdout for debugging purposes, e.g.
// cout << "this is a debug message" << endl;

int solution(string &S) {
    // write your code in C++14 (g++ 6.2.0)
    int len = S.length();
    stack<char> st;

    for(int i=0; i<len; i++){
        if(S[i] == '('){
            st.push(S[i]);
        }else{
            
        }
    }
}

Code: 14:40:51 UTC, cpp, autosave

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// you can use includes, for example:
#include <bits/stdc++.h>

// you can write to stdout for debugging purposes, e.g.
// cout << "this is a debug message" << endl;

int solution(string &S) {
    // write your code in C++14 (g++ 6.2.0)
    int len = S.length();
    stack<char> st;

    for(int i=0; i<len; i++){
        if(S[i] == '('){
            st.push(S[i]);
        }else{
            st.pop
        }
    }
}

Code: 14:41:22 UTC, cpp, autosave

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// you can use includes, for example:
#include <bits/stdc++.h>

// you can write to stdout for debugging purposes, e.g.
// cout << "this is a debug message" << endl;

int solution(string &S) {
    // write your code in C++14 (g++ 6.2.0)
    int len = S.length();
    stack<char> st;

    for(int i=0; i<len; i++){
        if(S[i] == '('){
            st.push(S[i]);
        }else{
            if(!st.empty()){
                st.pop();
            }

        }
    }
}

Code: 14:41:43 UTC, cpp, autosave

show code in pop-up

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// you can use includes, for example:
#include <bits/stdc++.h>

// you can write to stdout for debugging purposes, e.g.
// cout << "this is a debug message" << endl;

int solution(string &S) {
    // write your code in C++14 (g++ 6.2.0)
    int len = S.length();
    stack<char> st;

    if(len == 0){
        return 0;
    }

    for(int i=0; i<len; i++){
        if(S[i] == '('){
            st.push(S[i]);
        }else{
            if(!st.empty()){
                st.pop();
            }
        }
    }
}

Code: 14:41:53 UTC, cpp, autosave

show code in pop-up

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25

// you can use includes, for example:
#include <bits/stdc++.h>

// you can write to stdout for debugging purposes, e.g.
// cout << "this is a debug message" << endl;

int solution(string &S) {
    // write your code in C++14 (g++ 6.2.0)
    int len = S.length();
    stack<char> st;

    if(len == 0 || ){
        return 0;
    }

    for(int i=0; i<len; i++){
        if(S[i] == '('){
            st.push(S[i]);
        }else{
            if(!st.empty()){
                st.pop();
            }
        }
    }
}

Code: 14:42:04 UTC, cpp, autosave

show code in pop-up

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// you can use includes, for example:
#include <bits/stdc++.h>

// you can write to stdout for debugging purposes, e.g.
// cout << "this is a debug message" << endl;

int solution(string &S) {
    // write your code in C++14 (g++ 6.2.0)
    int len = S.length();
    stack<char> st;

    if(len == 0 || S[i] == ')'){
        return 0;
    }

    for(int i=0; i<len; i++){
        if(S[i] == '('){
            st.push(S[i]);
        }else{
            if(!st.empty()){
                st.pop();
            }
        }
    }
}

Code: 14:42:22 UTC, cpp, autosave

show code in pop-up

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25

// you can use includes, for example:
#include <bits/stdc++.h>

// you can write to stdout for debugging purposes, e.g.
// cout << "this is a debug message" << endl;

int solution(string &S) {
    // write your code in C++14 (g++ 6.2.0)
    int len = S.length();
    stack<char> st;

    if(len == 0 || len == 1 || S[i] == ')'){
        return 0;
    }

    for(int i=0; i<len; i++){
        if(S[i] == '('){
            st.push(S[i]);
        }else{
            if(!st.empty()){
                st.pop();
            }
        }
    }
}

Code: 14:42:52 UTC, cpp, autosave

show code in pop-up

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25

// you can use includes, for example:
#include <bits/stdc++.h>

// you can write to stdout for debugging purposes, e.g.
// cout << "this is a debug message" << endl;

int solution(string &S) {
    // write your code in C++14 (g++ 6.2.0)
    int len = S.length();
    stack<char> st;

    if(len S[i] == ')'){
        return 0;
    }

    for(int i=0; i<len; i++){
        if(S[i] == '('){
            st.push(S[i]);
        }else{
            if(!st.empty()){
                st.pop();
            }
        }
    }
}

Code: 14:43:02 UTC, cpp, autosave

show code in pop-up

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25

// you can use includes, for example:
#include <bits/stdc++.h>

// you can write to stdout for debugging purposes, e.g.
// cout << "this is a debug message" << endl;

int solution(string &S) {
    // write your code in C++14 (g++ 6.2.0)
    int len = S.length();
    stack<char> st;

    if(S[i] == ')'){
        return 0;
    }

    for(int i=0; i<len; i++){
        if(S[i] == '('){
            st.push(S[i]);
        }else{
            if(!st.empty()){
                st.pop();
            }
        }
    }
}

Code: 14:43:47 UTC, cpp, autosave

show code in pop-up

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// you can use includes, for example:
#include <bits/stdc++.h>

// you can write to stdout for debugging purposes, e.g.
// cout << "this is a debug message" << endl;

int solution(string &S) {
    // write your code in C++14 (g++ 6.2.0)
    int len = S.length();
    stack<char> st;

    if(S[i] == ')'){
        return 0;
    }

    for(int i=0; i<len; i++){
        if(S[i] == '('){
            st.push(S[i]);
        }else{
            if(!st.empty()){
                st.pop();
            }else
        }
    }
}

Code: 14:44:01 UTC, cpp, autosave

show code in pop-up

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// you can use includes, for example:
#include <bits/stdc++.h>

// you can write to stdout for debugging purposes, e.g.
// cout << "this is a debug message" << endl;

int solution(string &S) {
    // write your code in C++14 (g++ 6.2.0)
    int len = S.length();
    stack<char> st;

    if(S[i] == ')'){
        return 0;
    }

    for(int i=0; i<len; i++){
        if(S[i] == '('){
            st.push(S[i]);
        }else{
            if(!st.empty()){
                st.pop();
            }else{
                return 0;
            }
        }
    }

    for()
}

Code: 14:44:11 UTC, cpp, autosave

show code in pop-up

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// you can use includes, for example:
#include <bits/stdc++.h>

// you can write to stdout for debugging purposes, e.g.
// cout << "this is a debug message" << endl;

int solution(string &S) {
    // write your code in C++14 (g++ 6.2.0)
    int len = S.length();
    stack<char> st;

    if(S[i] == ')'){
        return 0;
    }

    for(int i=0; i<len; i++){
        if(S[i] == '('){
            st.push(S[i]);
        }else{
            if(!st.empty()){
                st.pop();
            }else{
                return 0;
            }
        }
    }

    
}

Code: 14:44:28 UTC, cpp, autosave

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// you can use includes, for example:
#include <bits/stdc++.h>

// you can write to stdout for debugging purposes, e.g.
// cout << "this is a debug message" << endl;

int solution(string &S) {
    // write your code in C++14 (g++ 6.2.0)
    int len = S.length();
    stack<char> st;

    if(S[i] == ')'){
        return 0;
    }

    for(int i=0; i<len; i++){
        if(S[i] == '('){
            st.push(S[i]);
        }else{
            if(!st.empty()){
                st.pop();
            }else{
                return 0;
            }
        }
    }

    if(st.empty())
}

Code: 14:44:43 UTC, cpp, autosave

show code in pop-up

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// you can use includes, for example:
#include <bits/stdc++.h>

// you can write to stdout for debugging purposes, e.g.
// cout << "this is a debug message" << endl;

int solution(string &S) {
    // write your code in C++14 (g++ 6.2.0)
    int len = S.length();
    stack<char> st;

    if(S[i] == ')'){
        return 0;
    }

    for(int i=0; i<len; i++){
        if(S[i] == '('){
            st.push(S[i]);
        }else{
            if(!st.empty()){
                st.pop();
            }else{
                return 0;
            }
        }
    }

    if(st.empty()){
        return 1;
    }else{
        return 0;
    }
}

Code: 14:45:16 UTC, cpp, verify, result: Failed

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// you can use includes, for example:
#include <bits/stdc++.h>

// you can write to stdout for debugging purposes, e.g.
// cout << "this is a debug message" << endl;

int solution(string &S) {
    // write your code in C++14 (g++ 6.2.0)
    int len = S.length();
    stack<char> st;

    if(S[i] == ')'){
        return 0;
    }

    for(int i=0; i<len; i++){
        if(S[i] == '('){
            st.push(S[i]);
        }else{
            if(!st.empty()){
                st.pop();
            }else{
                return 0;
            }
        }
    }

    if(st.empty()){
        return 1;
    }else{
        return 0;
    }
}

Analysis

Compile error

func.cpp: In function 'int solution(std::__cxx11::string&)':
func.cpp:12:10: error: 'i' was not declared in this scope
     if(S[i] == ')'){
          ^

Code: 14:45:51 UTC, cpp, autosave

show code in pop-up

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// you can use includes, for example:
#include <bits/stdc++.h>

// you can write to stdout for debugging purposes, e.g.
// cout << "this is a debug message" << endl;

int solution(string &S) {
    // write your code in C++14 (g++ 6.2.0)
    int len = S.length();
    stack<char> st;

    if(S[] == ')'){
        return 0;
    }

    for(int i=0; i<len; i++){
        if(S[i] == '('){
            st.push(S[i]);
        }else{
            if(!st.empty()){
                st.pop();
            }else{
                return 0;
            }
        }
    }

    if(st.empty()){
        return 1;
    }else{
        return 0;
    }
}

Code: 14:45:53 UTC, cpp, verify, result: Passed

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// you can use includes, for example:
#include <bits/stdc++.h>

// you can write to stdout for debugging purposes, e.g.
// cout << "this is a debug message" << endl;

int solution(string &S) {
    // write your code in C++14 (g++ 6.2.0)
    int len = S.length();
    stack<char> st;

    if(S[0] == ')'){
        return 0;
    }

    for(int i=0; i<len; i++){
        if(S[i] == '('){
            st.push(S[i]);
        }else{
            if(!st.empty()){
                st.pop();
            }else{
                return 0;
            }
        }
    }

    if(st.empty()){
        return 1;
    }else{
        return 0;
    }
}

Analysis

expand all Example tests

▶

example1
example test

✔

0.001 s

▶

example2
example test2

✔

0.001 s

Code: 14:46:14 UTC, cpp, verify, result: Passed

show code in pop-up

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// you can use includes, for example:
#include <bits/stdc++.h>

// you can write to stdout for debugging purposes, e.g.
// cout << "this is a debug message" << endl;

int solution(string &S) {
    // write your code in C++14 (g++ 6.2.0)
    int len = S.length();
    stack<char> st;

    for(int i=0; i<len; i++){
        if(S[i] == '('){
            st.push(S[i]);
        }else{
            if(!st.empty()){
                st.pop();
            }else{
                return 0;
            }
        }
    }

    if(st.empty()){
        return 1;
    }else{
        return 0;
    }
}

Analysis

expand all Example tests

▶

example1
example test

✔

0.001 s

▶

example2
example test2

✔

0.001 s

Code: 14:46:19 UTC, cpp, verify, result: Passed

show code in pop-up

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// you can use includes, for example:
#include <bits/stdc++.h>

// you can write to stdout for debugging purposes, e.g.
// cout << "this is a debug message" << endl;

int solution(string &S) {
    // write your code in C++14 (g++ 6.2.0)
    int len = S.length();
    stack<char> st;

    for(int i=0; i<len; i++){
        if(S[i] == '('){
            st.push(S[i]);
        }else{
            if(!st.empty()){
                st.pop();
            }else{
                return 0;
            }
        }
    }

    if(st.empty()){
        return 1;
    }else{
        return 0;
    }
}

Analysis

expand all Example tests

▶

example1
example test

✔

0.001 s

▶

example2
example test2

✔

0.001 s

Code: 14:46:24 UTC, cpp, final, score: 100

show code in pop-up

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// you can use includes, for example:
#include <bits/stdc++.h>

// you can write to stdout for debugging purposes, e.g.
// cout << "this is a debug message" << endl;

int solution(string &S) {
    // write your code in C++14 (g++ 6.2.0)
    int len = S.length();
    stack<char> st;

    for(int i=0; i<len; i++){
        if(S[i] == '('){
            st.push(S[i]);
        }else{
            if(!st.empty()){
                st.pop();
            }else{
                return 0;
            }
        }
    }

    if(st.empty()){
        return 1;
    }else{
        return 0;
    }
}

Analysis summary

The solution obtained perfect score.

Analysis

Detected time complexity:

O(N)

expand all Example tests

▶

example1
example test

✔

0.001 s

▶

example2
example test2

✔

0.001 s

expand all Correctness tests

▶

negative_match
invalid structure, but the number of parentheses matches

✔

0.001 s

▶

empty
empty string

✔

0.001 s

▶

simple_grouped
simple grouped positive and negative test, length=22

✔

0.001 s

▶

small_random

✔

0.001 s

expand all Performance tests

▶

large1
simple large positive and negative test, 10K or 10K+1 ('s followed by 10K )'s

✔

0.001 s

▶

large_full_ternary_tree
tree of the form T=(TTT) and depth 11, length=177K+

✔

0.004 s

0.001 s

▶

multiple_full_binary_trees
sequence of full trees of the form T=(TT), depths [1..10..1], with/without unmatched ')' at the end, length=49K+

✔

0.001 s

▶

broad_tree_with_deep_paths
string of the form (TTT...T) of 300 T's, each T being '(((...)))' nested 200-fold, length=1 million

✔

0.012 s

0.001 s