add new solutions

solutions/0/q63/solution.go

@@ -0,0 +1,28 @@
+package q63
+
+func uniquePathsWithObstacles(obstacleGrid [][]int) int {
+	w, h := len(obstacleGrid[0]), len(obstacleGrid)
+	if obstacleGrid[h-1][w-1]+obstacleGrid[0][0] > 0 {
+		return 0
+	}
+
+	obstacleGrid[h-1][w-1] = -1
+	for i := w + h - 2; i >= 0; i-- {
+		for x := min(i, w-1); x >= 0 && i-x < h; x-- {
+			y := i - x
+			if obstacleGrid[y][x] == 1 {
+				continue
+			}
+			if x+1 < w && obstacleGrid[y][x+1] != 1 {
+				obstacleGrid[y][x] += obstacleGrid[y][x+1]
+			}
+			if y+1 < h && obstacleGrid[y+1][x] != 1 {
+				obstacleGrid[y][x] += obstacleGrid[y+1][x]
+			}
+		}
+	}
+
+	return -1 * obstacleGrid[0][0]
+}
+
+var _ = uniquePathsWithObstacles