Valid Parentheses
Given a string containing just the characters '('
, ')'
, '{'
, '}'
, '['
and ']'
, determine if the input string is valid.
The brackets must close in the correct order, "()"
and "()[]{}"
are all valid but "(]"
and "([)]"
are not.
将左括号压入数组,然后遇到右括号时就与数组中的最后一个元素比较,匹配则继续下一个元素,不匹配输出false,直到所有的元素都执行一遍,期间如果遇到右括号时数组为空,则输出false,最后看数组的元素是否为0,是则输出true,否则输出false。
bool isValid(char *s) { char c[100]; int index = 0; for(int i = 0; i<strlen(s); i++){ if(s[i] == '(' || s[i] == '[' || s[i] == '{') c[index++] = s[i]; if(s[i] == ')' || s[i] == ']' || s[i] == '}'){ if(index == 0) return false; char r = c[index-1]; switch(s[i]){ case ')': if(r == '(') index--; else return false; break; case ']': if(r == '[') index--; else return false; break; case '}': if(r == '{') index--; else return false; break; } } } if(index == 0){ return true; } else{ return false; } }