feat: add question 64

Author: yinxin630

64.最小路径和.js

@@ -0,0 +1,26 @@
+/*
+ * @lc app=leetcode.cn id=64 lang=javascript
+ *
+ * [64] 最小路径和
+ */
+
+// @lc code=start
+/**
+ * @param {number[][]} grid
+ * @return {number}
+ */
+var minPathSum = function(grid) {
+    const dp = [];
+    for (let i = 0; i < grid.length; i++) {
+        dp[i] = [];
+        for (let j = 0; j < grid[0].length; j++) {
+            const min = Math.min(
+                (dp[i - 1] && dp[i - 1][j]) === undefined ? Number.MAX_SAFE_INTEGER : (dp[i - 1] && dp[i - 1][j]), 
+                dp[i][j - 1] === undefined ? Number.MAX_SAFE_INTEGER : dp[i][j - 1]
+            );
+            dp[i][j] = (min === Number.MAX_SAFE_INTEGER ? 0 : min) + grid[i][j];
+        }
+    }
+    return dp[grid.length - 1][grid[0].length - 1];
+};
+// @lc code=end