Add ValidParentheses (#3689)

This commit is contained in:
Aidar Djamalbek
2022-11-01 23:26:13 +06:00
committed by GitHub
parent fea982d54d
commit 1a391c2fe9
3 changed files with 59 additions and 0 deletions

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@ -0,0 +1,33 @@
package com.thealgorithms.strings;
// Given a string s containing just the characters '(', ')', '{', '}', '[' and ']', determine if the input string is valid.
// An input string is valid if:
// Open brackets must be closed by the same type of brackets.
// Open brackets must be closed in the correct order.
// Every close bracket has a corresponding open bracket of the same type.
public class ValidParentheses {
public static boolean isValid(String s) {
char[] stack = new char[s.length()];
int head = 0;
for(char c : s.toCharArray()) {
switch(c) {
case '{':
case '[':
case '(':
stack[head++] = c;
break;
case '}':
if(head == 0 || stack[--head] != '{') return false;
break;
case ')':
if(head == 0 || stack[--head] != '(') return false;
break;
case ']':
if(head == 0 || stack[--head] != '[') return false;
break;
}
}
return head == 0;
}
}