Merge pull request #52 from yungshenglu/develop

Merge develop into master

Author: David Lu

LC-412/LC-412.cpp

@@ -12,14 +12,15 @@ class Solution {
     vector<string> fizzBuzz(int n) {
         vector<string> result;
         for (int i = 1; i <= n; ++i) {
-            if (i % 15 == 0)
-                result.push_back("FizzBuzz");
-            else if (i % 5 == 0 && i % 3 != 0)
-                result.push_back("Buzz");
-            else if (i % 3 == 0 && i % 5 != 0)
-                result.push_back("Fizz");
-            else
-                result.push_back(to_string(i));
+            cout << i << endl;
+            string temp = "";
+            if (i % 3 == 0) {
+                temp += "Fizz";
+            }
+            if (i % 5 == 0) {
+                temp += "Buzz";
+            }
+            result.push_back(temp != "" ? temp : to_string(i));
         }
         return result;
     }

LC-412/LC-412.js

@@ -0,0 +1,23 @@
+/**
+ * @param {number} n
+ * @return {string[]}
+ */
+var fizzBuzz = function(n) {
+  /**
+   * Concepts:
+   * Optimize naive approach
+   */
+
+  let result = [];
+  for (let i = 1; i <= n; ++i) {
+    let temp = '';
+    if (i % 3 === 0) {
+      temp += 'Fizz';
+    }
+    if (i % 5 === 0) {
+      temp += 'Buzz';
+    }
+    result.push(temp ? temp : String(i));
+  }
+  return result;
+};

LC-73/LC-73-1.js

@@ -0,0 +1,33 @@
+/**
+ * @param {number[][]} matrix
+ * @return {void} Do not return anything, modify matrix in-place instead.
+ */
+var setZeroes = function(matrix) {
+  /**
+   * Concepts:
+   * 1. Get the index of row and column that should be zero in matrix
+   * 2. Set the element that should be zero
+   */
+
+  let zeroRowIndex = new Set();
+  let zeroColIndex = new Set();
+
+  for (let i = 0; i < matrix.length; ++i) {
+      for (let j = 0; j < matrix[i].length; ++j) {
+          if (matrix[i][j] === 0) {
+              zeroRowIndex.add(i);
+              zeroColIndex.add(j);
+          }
+      }
+  }
+
+  for (let i = 0; i < matrix.length; ++i) {
+      for (let j = 0; j < matrix[i].length; ++j) {
+          if (zeroRowIndex.has(i) || zeroColIndex.has(j)) {
+              matrix[i][j] = 0;
+          }
+      }
+  }
+
+  return matrix;
+};

LC-73/README.md

@@ -0,0 +1,47 @@
+# LC-73 - Set Matrix Zeroes
+
+Given an `m x n` integer matrix `matrix`, if an element is `0`, set its entire row and column to `0`'s.
+
+You must do it in place.
+
+> * Difficulty: **MEDIUM**
+
+---
+## Examples
+
+![](../res/img/LC-73-1.jpeg)
+
+```
+Input: matrix = [[1,1,1],[1,0,1],[1,1,1]]
+Output: [[1,0,1],[0,0,0],[1,0,1]]
+```
+
+![](../res/img/LC-73-2.jpeg)
+
+```
+Input: matrix = [[0,1,2,0],[3,4,5,2],[1,3,1,5]]
+Output: [[0,0,0,0],[0,4,5,0],[0,3,1,0]]
+```
+
+---
+## Notes
+
+- `m == matrix.length`
+- `n == matrix[0].length`
+- `1 <= m, n <= 200`
+- `-231 <= matrix[i][j] <= 231 - 1`
+
+---
+## Follow Up
+
+- A straightforward solution using $O(mn)$ space is probably a bad idea.
+- A simple improvement uses $O(m + n)$ space, but still not the best solution.
+- Could you devise a constant space solution?
+
+---
+## Solutions
+
+1. Additional Memory Approach
+  - Time complexity: $O(mn)$
+  - Space complexity: $O(m + n)$
+