add minimum-falling-path-sum but time limit exceed

src/dp/minimum_falling_path_sum.rs

@@ -0,0 +1,48 @@
+//! https://leetcode.cn/problems/minimum-falling-path-sum
+fn min_falling_path_sum(matrix: Vec<Vec<i32>>) -> i32 {
+    let m = matrix.len();
+    let n = matrix[0].len();
+
+    let mut min = i32::MAX;
+    for j in 0..n {
+        min = min.min(search(0, j, m, n, 0, &matrix));
+    }
+
+    min
+}
+
+fn search(row: usize, col:usize, m: usize, n: usize, mut sum: i32, matrix: &Vec<Vec<i32>>) -> i32 {
+    if row == m {
+        return sum;
+    }
+    let cur_val = matrix[row][col];
+    sum += cur_val;
+    let mut min = search(row+1,col, m, n, sum, matrix);
+    if col >= 1 {
+        min = min.min(search(row+1,col-1, m, n, sum, matrix));
+    }
+    if col < n-1 {
+        min = min.min(search(row+1,col+1, m, n, sum, matrix));
+    }
+    min
+}
+
+#[test]
+fn test() {
+    for (matrix, min_path_sum) in [
+        (
+            vec_vec![
+                [-19,57],[-40,-5]
+            ],
+            -59
+        ),
+        (
+            vec_vec![
+                [2,1,3],[6,5,4],[7,8,9]
+            ],
+            13
+        )
+    ] {
+        assert_eq!(min_falling_path_sum(matrix), min_path_sum);
+    }
+}

src/dp/mod.rs

@@ -34,3 +34,4 @@ mod stone_game;
 mod trapping_rain_water;
 mod triangle;
 mod unique_paths;
+mod minimum_falling_path_sum;