Add 63_Unique_Paths_II.java

Author: Sean Prashad

Dynamic Programming/63_Unique_Paths_II.java

@@ -0,0 +1,44 @@
+class Solution {
+ public int uniquePathsWithObstacles(int[][] obstacleGrid) {
+ if (obstacleGrid == null || obstacleGrid.length == 0) {
+ return 0;
+ }
+
+ int rows = obstacleGrid.length, cols = obstacleGrid[0].length;
+ int[][] dp = new int[rows][cols];
+
+ for (int i = 0; i < rows; i++) {
+ if (obstacleGrid[i][0] == 0) {
+ dp[i][0] = 1;
+ } else {
+ while (i < rows) {
+ dp[i][0] = 0;
+ ++i;
+ }
+ }
+ }
+
+ for (int j = 0; j < cols; j++) {
+ if (obstacleGrid[0][j] == 0) {
+ dp[0][j] = 1;
+ } else {
+ while (j < cols) {
+ dp[0][j] = 0;
+ ++j;
+ }
+ }
+ }
+
+ for (int i = 1; i < rows; i++) {
+ for (int j = 1; j < cols; j++) {
+ if (obstacleGrid[i][j] == 1) {
+ dp[i][j] = 0;
+ continue;
+ }
+ dp[i][j] = dp[i - 1][j] + dp[i][j - 1];
+ }
+ }
+
+ return dp[rows - 1][cols - 1];
+ }
+}