Merge pull request neetcode-gh#981 from andra961/main

Create: 76-Minimum-Window-Substring.ts

typescript/76-Minimum-Window-Substring.ts

@@ -0,0 +1,48 @@
+function minWindow(s: string, t: string): string {
+ let minL = 0;
+ let minR = s.length;
+
+ //create string t hashmap and needed
+ const tCount = {};
+ let needed = 0;
+ for (let i = 0; i < t.length; i++) {
+ if (t[i] in tCount) tCount[t[i]]++;
+ else {
+ tCount[t[i]] = 1;
+ needed++;
+ }
+ }
+
+ //initialize winCount(empty)
+ const winCount = {};
+ let matched = 0;
+
+ let l = 0;
+
+ for (let r = 0; r < s.length; r++) {
+ //update winCount with adding s[r]
+ if (s[r] in winCount) winCount[s[r]]++;
+ else winCount[s[r]] = 1;
+ //update matched
+ if (s[r] in tCount && winCount[s[r]] === tCount[s[r]]) matched++;
+
+ //the window is valid
+ while (matched === needed) {
+ //update min
+ if (r - l + 1 < minR - minL + 1) {
+ minL = l;
+ minR = r;
+ }
+
+ //remove l
+ //update matched
+ if (s[l] in tCount && winCount[s[l]] === tCount[s[l]]) matched--;
+ //update winCount with the removal of s[l]
+ winCount[s[l]]--;
+ if (winCount[s[l]] === 0) delete winCount[s[l]];
+ l++;
+ }
+ }
+
+ return minR - minL + 1 > s.length ? '' : s.slice(minL, minR + 1);
+}