Create Search-a-2D-Matrix-II.js

LeetcodeProblems/Search-a-2D-Matrix-II.js

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+/*
+https://leetcode.com/problems/search-a-2d-matrix-ii/description/
+ Write an efficient algorithm that searches for a value in an m x n matrix. This matrix has the following properties:
+ Integers in each row are sorted in ascending from left to right.
+Integers in each column are sorted in ascending from top to bottom.
+Example:
+ Consider the following matrix:
+ [
+  [1,   4,  7, 11, 15],
+  [2,   5,  8, 12, 19],
+  [3,   6,  9, 16, 22],
+  [10, 13, 14, 17, 24],
+  [18, 21, 23, 26, 30]
+]
+Given target = 5, return true.
+Given target = 20, return false.
+*/
+
+/**
+* @param {number[][]} matrix
+* @param {number} target
+* @return {boolean}
+*/
+var searchMatrix = function(matrix, target) {
+  if (matrix.length == 0)
+      return false
+  var lastCol = matrix[0].length - 1;
+  var firstRow = 0;
+
+  while(lastCol >= 0 && firstRow < matrix.length) {
+      if(matrix[firstRow][lastCol] == target) {
+          return true;
+      } else if(matrix[firstRow][lastCol] > target) {
+          lastCol--;
+      } else {
+          firstRow++;
+      }
+  }
+
+  return false;
+};
+
+const matrix1 = [
+  [1,4,7,    11,15],
+  [2,5,8,    12,19],
+  [3,6,9,    16,22],
+  [10,13,14, 17,24],
+  [18,21,23, 26,30]
+];
+
+var main = function(n) {
+  console.log(searchMatrix(matrix1, 5));
+  console.log(searchMatrix(matrix1, 0));
+  console.log(searchMatrix(matrix1, 15));
+}
+
+module.exports.main = main;