Update solution for number-of-submatrices-that-sum-to-target w/ id 1370018858

Time: 144 ms
MemUsage: 2.2 MB

leetcode/number-of-submatrices-that-sum-to-target/solution_1370018858.rs

@@ -0,0 +1,29 @@
+impl Solution {
+    pub fn num_submatrix_sum_target(matrix: Vec<Vec<i32>>, target: i32) -> i32 {
+        let (len_x, len_y) = (matrix.len() + 1, matrix[0].len() + 1);
+        let mut matrix_sum = vec![vec![0i32; len_y]; len_x]; 
+
+        for x in 1..len_x{
+            for y in 1..len_y{
+                matrix_sum[x][y] = matrix[x - 1][y - 1] + matrix_sum[x - 1][y] + matrix_sum[x][y - 1] - matrix_sum[x - 1][y - 1];
+            }
+        }
+
+        let mut count = 0;
+        let mut sum = 0;
+        for lt_x in 1..len_x{
+            for lt_y in 1..len_y{
+                for rb_x in lt_x..len_x{
+                    for rb_y in lt_y..len_y{
+                        sum = matrix_sum[rb_x][rb_y] - matrix_sum[lt_x - 1][rb_y] - matrix_sum[rb_x][lt_y - 1] + matrix_sum[lt_x - 1][lt_y - 1];
+                        if sum == target{
+                            count += 1;
+                        }
+                    }
+                }
+            }
+        }
+        
+        return count;
+    }
+}