Daily temperatures

stack/DailyTemperatures.js

@@ -0,0 +1,42 @@
+// Given an array of integers temperatures represents the daily temperatures,
+// return an array answer such that answer[i] is the number of days you have to wait after the ith day to get a warmer temperature.
+// If there is no future day for which this is possible, keep answer[i] == 0 instead.
+
+const temperatures = [73, 74, 75, 71, 69, 72, 76, 73];
+
+const dailyTemperatures = function (temperatures) {
+  const minStack = [];
+
+  temperatures.forEach((tem, idx) => {
+    let count = 0;
+    console.log("tem" + tem);
+    for (let i = idx + 1; i < temperatures.length; i++) {
+      const afeterNum = temperatures[i];
+
+      if (idx === temperatures.length - 1) {
+        count = 0;
+        break;
+      }
+
+      if (tem < afeterNum) {
+        count += 1;
+        break;
+      }
+
+      if (tem > afeterNum && idx + 1 === temperatures.length - 1) {
+        count = 0;
+        break;
+      }
+      count += 1;
+    }
+
+    minStack.push(count);
+  });
+
+  return minStack;
+};
+
+const x = dailyTemperatures(temperatures);
+console.log(x);
+
+// https://leetcode.com/problems/daily-temperatures/description/

stack/MinStack.js

@@ -15,7 +15,7 @@
  */
 
 var MinStack = function () {
-  this.array = [];
+  this.stack = [];
   this.minStack = [];
 };
 
@@ -25,14 +25,17 @@ var MinStack = function () {
  */
 
 MinStack.prototype.push = function (val) {
-  this.array.push(val);
+  const minStackTop = this.minStack.length - 1;
+  const stackTop = this.stack.length - 1;
 
-  if (
-    this.minStack[this.minStack.length - 1] >
-    this.array[this.minStack.length - 1]
-  ) {
-    this.minStack.push(this.minStack[this.minStack.length - 1]);
+  this.stack.push(val); // By default, the stack has a push
+
+  // Compare the numbers in the Top of stack and minStack.
+  if (this.minStack[minStackTop] > this.stack[stackTop]) {
+    // If the number in the minStack is smaller, then push
+    this.minStack.push(this.minStack[minStackTop]);
   } else {
+    // If the number in the minStack is larger, push the value currently coming into the minStak.
     this.minStack.push(val);
   }
 };
@@ -41,15 +44,15 @@ MinStack.prototype.push = function (val) {
  * @return {void}
  */
 MinStack.prototype.pop = function () {
-  this.array = this.array.slice(0, this.array.length - 1);
+  this.stack = this.stack.slice(0, this.stack.length - 1);
   this.minStack = this.minStack.slice(0, this.minStack.length - 1);
 };
 
 /**
  * @return {number}
  */
 MinStack.prototype.top = function () {
-  return this.array[this.array.length - 1];
+  return this.stack[this.stack.length - 1];
 };
 
 /**

stack/ValidParentheses.js

@@ -0,0 +1,27 @@
+const isValid = function (s) {
+  const stack = [];
+
+  const a = "()";
+  const b = "[]";
+  const c = "{}";
+
+  for (let i = 0; i < s.length; i++) {
+    const x = s[i];
+    const v = stack[stack.length - 1];
+    const word = x + v;
+
+    if (word == a || word == b || word == c) {
+      stack.pop();
+    } else {
+      stack.push(x);
+    }
+  }
+
+  return stack.length ? true : false;
+};
+
+const s = "()";
+const n = "()";
+const x = "(]";
+
+console.log(isValid(s));