add: Set Matrix Zeroes

Author: hijiangtao

README.md

@@ -18,6 +18,7 @@ This is the solution collection of my LeetCode problems, most of them are progra
 |48|[Rotate Image](https://leetcode.com/problems/rotate-image/) | [JavaScript](./src/rotate-image/res.js)|Medium|
 |66|[Plus One](https://leetcode.com/problems/plus-one/) | [JavaScript](./src/plus-one/res.js)|Easy|
 |69|[Sqrt(x)](https://leetcode.com/problems/sqrtx/) | [JavaScript](./src/sqrtx/res.js)|Easy|
+|73|[Set Matrix Zeroes](https://leetcode.com/problems/set-matrix-zeroes/) | [JavaScript](./src/set-matrix-zeroes/res.js)|Medium|
 |175|[Combine Two Tables](https://leetcode.com/problems/combine-two-tables/)| [SQL](./src/combine-two-tables/res.txt)|Easy|
 |176|[Second Highest Salary](https://leetcode.com/problems/second-highest-salary/)| [SQL](./src/second-highest-salary/res.txt)|Easy|
 |177|[Nth Highest Salary](https://leetcode.com/problems/nth-highest-salary/)| [SQL](./src/nth-highest-salary/res.txt)|Medium|

src/set-matrix-zeroes/res.js

@@ -0,0 +1,98 @@
+/**
+ * Given a m x n matrix, if an element is 0, set its entire row and column to 0. Do it in place.
+ * 
+ * Follow up:
+ * 
+ * Did you use extra space?
+ * A straight forward 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?
+ * 
+ * res.js
+ * @authors Joe Jiang (hijiangtao@gmail.com)
+ * @date    2017-02-28 13:49:19
+ * @version $Id$
+ * 
+ * @param {number[][]} matrix
+ * @return {void} Do not return anything, modify matrix in-place instead.
+ */
+let setZeroes = function(matrix) {
+    if (!matrix.length) {
+        return ;    
+    }
+    
+    let rowlen = matrix.length,
+        collen = matrix[0].length,
+        rowzero = false,
+        colzero = false;
+    
+    for (let i=0; i<rowlen; i++) {
+        for (let j=0; j<collen; j++) {
+            if (matrix[i][j] === 0) {
+                matrix[i][0] = 0;
+                matrix[0][j] = 0;
+                
+                if (i === 0) {
+                    rowzero = true;
+                }
+                if (j === 0) {
+                    colzero = true;
+                }
+            }
+        }
+    }
+    
+    for (let i=1; i<rowlen; i++) {
+        for (let j=1; j<collen; j++) {
+            if (matrix[i][0] === 0 || matrix[0][j] === 0) {
+                matrix[i][j] = 0;
+            }
+        }
+    }
+    
+    if (rowzero) {
+        for (let i=0; i<collen; i++) {
+            matrix[0][i] = 0;
+        }
+    }
+    if (colzero) {
+        for (let i=0; i<rowlen; i++) {
+            matrix[i][0] = 0;
+        }
+    }
+};
+
+// Another solution
+let setZeroes = function(matrix) {
+    if (!matrix.length) {
+        return ;    
+    }
+    
+    let rowlen = matrix.length,
+        collen = matrix[0].length,
+        colzero = false;
+    
+    for (let i=0; i<rowlen; i++) {
+        if (matrix[i][0] === 0) {
+            colzero = true;
+        }
+        for (let j=1; j<collen; j++) {
+            if (matrix[i][j] === 0) {
+                matrix[i][0] = 0;
+                matrix[0][j] = 0;
+            }
+        }
+    }
+    
+    for (let i=rowlen-1; i>=0; i--) {
+        for (let j=collen-1; j>=1; j--) {
+            if (matrix[i][0] === 0 || matrix[0][j] === 0) {
+                matrix[i][j] = 0;
+            }
+        }
+        
+        if (colzero) {
+            matrix[i][0] = 0;
+        }
+    }
+};