week6-unique_paths_ii

70works/week6/unique_paths_ii.js

+/**
+ * @param {number[][]} obstacleGrid
+ * @return {number}
+ */
+/**
+ * @param {number[][]} obstacleGrid
+ * @return {number}
+ */
+var uniquePathsWithObstacles = function(obstacleGrid) {
+
+    if(obstacleGrid.length <0) return 0;
+    if(obstacleGrid[0][0] === 1) return 0;
+    let row = obstacleGrid.length;
+    let col = obstacleGrid[0].length;
+    const dp = Array.apply(null, {length: row + 1}).map(
+        ()=> Array.apply(null, {length: col + 1}).map(() => 0));
+    dp[1][1] = 1;
+
+    //遍历的length得用dp的长度，而不能用obstacleGrid的长度
+    for(let i = 1; i < dp.length; i++) {
+        for(let j = 1; j < dp[i].length; j++) {
+            if(obstacleGrid[i-1][j-1] === 1 || i === 1 && j === 1) continue;
+            dp[i][j] = dp[i-1][j] + dp [i][j-1];
+        }
+    }
+    console.error(dp[row][col]);
+    return dp[row][col];
+};
+let obsobstacleGrid =  [[0,0,0],[0,1,0],[0,0,0]];
+uniquePathsWithObstacles(obsobstacleGrid);
\ No newline at end of file