* @param {string} s
* @return {boolean}
*/
var checkValidString = function (s) {
var leftMin = 0;
var leftMax = 0;
for (var c of s) {
if (c === '(') {
leftMin++;
leftMax++;
} else if (c === ')') {
leftMin--;
leftMax--;
} else {
leftMin--;
leftMax++;
}
if (leftMax < 0) {
return false;
}
if (leftMin < 0) {
leftMin = 0;
}
}
return leftMin === 0;
};
* https://leetcode.com/problems/valid-parenthesis-string/
* Time O(N^3) | Space O(N^2)
* @param {string} s
* @return {boolean}
*/
var checkValidString = function (s) {
const isBaseCase = s.length === 0;
if (isBaseCase) return true;
const dp = new Array(s.length)
.fill()
.map(() => new Array(s.length).fill(false));
for (let i = 0; i < s.length; i++) {
if (isStar(s[i])) dp[i][i] = true;
const isInBound = i < s.length - 1;
const isOpenedOrStar = isOpened(s[i]) || isStar(s[i]);
const isClosedOrStar = isClosed(s[i + 1]) || isStar(s[i + 1]);
const isValid = isInBound && isOpenedOrStar && isClosedOrStar;
if (isValid) dp[i][i + 1] = true;
}
for (let size = 2; size < s.length; size++) {
for (let i = 0; i + size < s.length; i++) {
const isStarOrDP = isStar(s[i]) && isDP(dp, i + 1, i + size);
if (isStarOrDP) {
dp[i][i + size] = true;
continue;
}
const isOpenedOrStar = isOpened(s[i]) || isStar(s[i]);
if (isOpenedOrStar) check(dp, size, i);
}
}
return dp[0][s.length - 1];
};
const check = (dp, size, i) => {
for (let k = i + 1; k <= i + size; k++) {
const isClosedOrStar = isClosed(s[k]) || isStar(s[k]);
const isKOrDP = isKEqual(k, i, 1) || isDP(dp, i + 1, k - 1);
const isKOrDPSize = isKEqual(k, i, size) || isDP(dp, k + 1, i + size);
const isValid = isClosedOrStar && isKOrDP && isKOrDPSize;
if (isValid) dp[i][i + size] = true;
}
};
var isStar = (char) => char === '*';
var isOpened = (char) => char === '(';
var isClosed = (char) => char === ')';
const isKEqual = (k, i, size) => k === i + size;
const isDP = (dp, i, k) => dp[i][k];
* Time O(N) | Space O(1)
* @param {string} s
* @return {boolean}
*/
var checkValidString = function (s) {
let [left, right] = [0, 0];
for (const char of s) {
left += isOpened(char) ? 1 : -1;
right += !isClosed(char) ? 1 : -1;
const isNegative = right < 0;
if (isNegative) break;
left = Math.max(left, 0);
}
return left === 0;
};
var isOpened = (char) => char === '(';
var isClosed = (char) => char === ')';