62:不同路径

src/main/java/leetcode/editor/cn/UniquePaths.java

@@ -64,8 +64,19 @@ public class UniquePaths {
     //leetcode submit region begin(Prohibit modification and deletion)
     class Solution {
         public int uniquePaths(int m, int n) {
-            int max = Math.max(m, n);
-            return max * (max + 1) / 2;
+            int[][] f = new int[m][n];
+            for (int i = 0; i < m; ++i) {
+                f[i][0] = 1;
+            }
+            for (int j = 0; j < n; ++j) {
+                f[0][j] = 1;
+            }
+            for (int i = 1; i < m; ++i) {
+                for (int j = 1; j < n; ++j) {
+                    f[i][j] = f[i - 1][j] + f[i][j - 1];
+                }
+            }
+            return f[m - 1][n - 1];
         }
     }
 //leetcode submit region end(Prohibit modification and deletion)