Test results - Codility

Tasks Details

easy

1. Brackets

Determine whether a given string of parentheses (multiple types) is properly nested.

Task Score

100%

Correctness

100%

Performance

100%

A string S consisting of N characters is considered to be properly nested if any of the following conditions is true:

S is empty;

S has the form "(U)" or "[U]" or "{U}" where U is a properly nested string;

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

For example, the string "{[()()]}" is properly nested but "([)()]" is not.

Write a function:

def solution(S)

that, given a string S consisting of N characters, returns 1 if 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..200,000];

string S is made only of the following characters: '(', '{', '[', ']', '}' and/or ')'.

Solution

Programming language used Python

Time spent on task 7 minutes

Notes

not defined yet

Task timeline

Code: 17:34:58 UTC, java, autosave

show code in pop-up

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: 17:35:08 UTC, py, autosave

show code in pop-up

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

# you can write to stdout for debugging purposes, e.g.
# print("this is a debug message")

def solution(S):
    stack = []
    brackets = {"(":")", "{":"}", "[":"]"}
    for s in S:
        if s in brackets.keys():
            stack.append(s)
        elif s in brackets.values():
            if stack:
                c = stack.pop()
                if brackets[c] != s:
                    return 0
    if stack:
        return 0
    return 1

Code: 17:35:38 UTC, py, 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

# you can write to stdout for debugging purposes, e.g.
# print("this is a debug message")

def solution(S):
    stack = []
    brackets = {"(":")", "{":"}", "[":"]"}
    for s in S:
        if s in brackets.keys():
            stack.append(s)
        elif s in brackets.values():
            if stack:
                c = stack.pop()
                if brackets[c] != s:
                    return 0
        else:
            
    if stack:
        return 0
    return 1

Code: 17:35:54 UTC, py, 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

# you can write to stdout for debugging purposes, e.g.
# print("this is a debug message")

def solution(S):
    stack = []
    brackets = {"(":")", "{":"}", "[":"]"}
    for s in S:
        if s in brackets.keys():
            stack.append(s)
        elif s in brackets.values():
            if stack:
                c = stack.pop()
                if brackets[c] != s:
                    return 0
        if stack:
            return 0
    if stack:
        return 0
    return 1

Code: 17:36:18 UTC, py, verify, result: Failed

show code in pop-up

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19

# you can write to stdout for debugging purposes, e.g.
# print("this is a debug message")

def solution(S):
    stack = []
    brackets = {"(":")", "{":"}", "[":"]"}
    for s in S:
        if s in brackets.keys():
            stack.append(s)
        elif s in brackets.values():
            if stack:
                c = stack.pop()
                if brackets[c] != s:
                    return 0
        if stack:
            return 0
    if stack:
        return 0
    return 1

User test case 1:

['TTTTTTT[a]TTTTTTTTTTT']

Analysis

expand all Example tests

▶

example1
example test 1

✘

WRONG ANSWER
got 0 expected 1

0.036 s

WRONG ANSWER, got 0 expected 1

▶

example2
example test 2

✔

0.036 s

expand all User tests

▶

test_data1

✔

0.036 s

OK
function result: 0

Code: 17:36:34 UTC, py, autosave

show code in pop-up

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18

# you can write to stdout for debugging purposes, e.g.
# print("this is a debug message")

def solution(S):
    stack = []
    brackets = {"(":")", "{":"}", "[":"]"}
    for s in S:
        if s in brackets.keys():
            stack.append(s)
        elif s in brackets.values():
            if stack:
                c = stack.pop()
                if brackets[c] != s:
                    return 0

    if stack:
        return 0
    return 1

Code: 17:36:36 UTC, py, verify, result: Passed

show code in pop-up

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

# you can write to stdout for debugging purposes, e.g.
# print("this is a debug message")

def solution(S):
    stack = []
    brackets = {"(":")", "{":"}", "[":"]"}
    for s in S:
        if s in brackets.keys():
            stack.append(s)
        elif s in brackets.values():
            if stack:
                c = stack.pop()
                if brackets[c] != s:
                    return 0
    if stack:
        return 0
    return 1

User test case 1:

['TTTTTTT[a]TTTTTTTTTTT']

Analysis

expand all Example tests

▶

example1
example test 1

✔

0.036 s

▶

example2
example test 2

✔

0.036 s

expand all User tests

▶

test_data1

✔

0.036 s

OK
function result: 1

Code: 17:40:52 UTC, py, autosave

show code in pop-up

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18

# you can write to stdout for debugging purposes, e.g.
# print("this is a debug message")

def solution(S):
    stack = []
    brackets = {"(":")", "{":"}", "[":"]"}
    for s in S:
        if s in brackets.keys():
            stack.append(s)
        elif s in brackets.values():
            
            if stack:
                c = stack.pop()
                if brackets[c] != s:
                    return 0
    if stack:
        return 0
    return 1

Code: 17:41:07 UTC, py, 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

# you can write to stdout for debugging purposes, e.g.
# print("this is a debug message")

def solution(S):
    stack = []
    brackets = {"(":")", "{":"}", "[":"]"}
    for s in S:
        if s in brackets.keys():
            stack.append(s)
        elif s in brackets.values():
            if stack:
                c = stack.pop()
                if brackets[c] != s:
                    return 0
            else:
                return 0
    if stack:
        return 0
    return 1

Code: 17:41:10 UTC, py, verify, result: Passed

show code in pop-up

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19

# you can write to stdout for debugging purposes, e.g.
# print("this is a debug message")

def solution(S):
    stack = []
    brackets = {"(":")", "{":"}", "[":"]"}
    for s in S:
        if s in brackets.keys():
            stack.append(s)
        elif s in brackets.values():
            if stack:
                c = stack.pop()
                if brackets[c] != s:
                    return 0
            else:
                return 0
    if stack:
        return 0
    return 1

User test case 1:

['TTTTTTT[a]TTTTTTTTTTT']

Analysis

expand all Example tests

▶

example1
example test 1

✔

0.036 s

▶

example2
example test 2

✔

0.036 s

expand all User tests

▶

test_data1

✔

0.036 s

OK
function result: 1

Code: 17:41:33 UTC, py, verify, result: Passed

show code in pop-up

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19

# you can write to stdout for debugging purposes, e.g.
# print("this is a debug message")

def solution(S):
    stack = []
    brackets = {"(":")", "{":"}", "[":"]"}
    for s in S:
        if s in brackets.keys():
            stack.append(s)
        elif s in brackets.values():
            if stack:
                c = stack.pop()
                if brackets[c] != s:
                    return 0
            else:
                return 0
    if stack:
        return 0
    return 1

User test case 1:

['TTTTTTT[a]TTTTTTTTTTT']

Analysis

expand all Example tests

▶

example1
example test 1

✔

0.036 s

▶

example2
example test 2

✔

0.036 s

expand all User tests

▶

test_data1

✔

0.036 s

OK
function result: 1

Code: 17:41:36 UTC, py, final, score: 100

show code in pop-up

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19

# you can write to stdout for debugging purposes, e.g.
# print("this is a debug message")

def solution(S):
    stack = []
    brackets = {"(":")", "{":"}", "[":"]"}
    for s in S:
        if s in brackets.keys():
            stack.append(s)
        elif s in brackets.values():
            if stack:
                c = stack.pop()
                if brackets[c] != s:
                    return 0
            else:
                return 0
    if stack:
        return 0
    return 1

Analysis summary

The solution obtained perfect score.

Analysis

Detected time complexity:

O(N)

expand all Example tests

▶

example1
example test 1

✔

0.036 s

▶

example2
example test 2

✔

0.036 s

expand all Correctness tests

▶

negative_match
invalid structures

✔

0.036 s

▶

empty
empty string

✔

0.036 s

▶

simple_grouped
simple grouped positive and negative test, length=22

✔

0.036 s

expand all Performance tests

▶

large1
simple large positive test, 100K ('s followed by 100K )'s + )(

✔

0.104 s

0.036 s

0.044 s

▶

large2
simple large negative test, 10K+1 ('s followed by 10K )'s + )( + ()

✔

0.044 s

0.036 s

▶

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

✔

0.096 s

▶

multiple_full_binary_trees
sequence of full trees of the form T=(TT), depths [1..10..1], with/without some brackets at the end, length=49K+

✔

0.056 s

0.052 s

0.036 s

▶

broad_tree_with_deep_paths
string of the form [TTT...T] of 300 T's, each T being '{{{...}}}' nested 200-fold, length=120K+

✔

0.080 s