string O(n) O(n)

Author: lukeist

leetcode-844-backspaceStringCompare.js

@@ -0,0 +1,63 @@
+/**
+ * @param {string} s
+ * @param {string} t
+ * @return {boolean}
+ */
+
+// p: str, str
+// r: boolean
+
+//   i
+// ab#c
+//   j
+// ad#c
+
+var backspaceCompare = function (s, t) {
+  let i = s.length - 1,
+    j = t.length - 1;
+  let skipS = 0,
+    skipT = 0;
+
+  while (i >= 0 || j >= 0) {
+    while (i >= 0) {
+      console.log(skipS, i, skipT, j);
+      if (s[i] === "#") {
+        skipS++;
+        i--;
+      } else if (skipS > 0) {
+        skipS--;
+        i--;
+      } else break;
+    }
+
+    while (j >= 0) {
+      if (t[j] === "#") {
+        skipT++;
+        j--;
+      } else if (skipT > 0) {
+        skipT--;
+        j--;
+      } else break;
+    }
+    if (i >= 0 && j >= 0 && s[i] !== t[j]) return false;
+    if (i >= 0 !== j >= 0) return false;
+    i--;
+    j--;
+  }
+
+  return true;
+};
+
+// O(n) O(n)
+// var backspaceCompare = function(s, t) {
+//     return getStr(s) === getStr(t);
+// };
+// const getStr = (str) => {
+//     let stack = [];
+//     for (let c of str) {
+//         c === '#' ? stack.pop() : stack.push(c);
+//     }
+//     return stack.join('');
+// }
+
+console.log(backspaceCompare("aaa###", "a#a#a#"));