feat: 1504_count_submatrices_with_all_ones

1504_count_submatrices_with_all_ones/Cargo.lock

@@ -0,0 +1,7 @@
+# This file is automatically @generated by Cargo.
+# It is not intended for manual editing.
+version = 4
+
+[[package]]
+name = "count_submatrices_with_all_ones"
+version = "0.1.0"

1504_count_submatrices_with_all_ones/Cargo.toml

@@ -0,0 +1,6 @@
+[package]
+name = "count_submatrices_with_all_ones"
+version = "0.1.0"
+edition = "2024"
+
+[dependencies]

1504_count_submatrices_with_all_ones/src/lib.rs

@@ -0,0 +1,48 @@
+pub struct Solution;
+
+impl Solution {
+    pub fn num_submat(matrix: Vec<Vec<i32>>) -> i32 {
+        let m = matrix.len();
+        let n = matrix[0].len();
+
+        let mut result = 0;
+        let mut heights = vec![0; n];
+        for i in 0..m {
+            for j in 0..n {
+                if matrix[i][j] == 1 {
+                    heights[j] += matrix[i][j];
+                } else {
+                    heights[j] = 0;
+                }
+            }
+
+            let mut index_stack: Vec<usize> = vec![];
+            let mut previos_less_index = vec![-1 as isize; n];
+            for j in 0..n {
+                while let Some(&index) = index_stack.last() {
+                    if heights[j] > heights[index] {
+                        previos_less_index[j] = index as isize;
+                        break;
+                    } else {
+                        index_stack.pop();
+                    }
+                }
+                index_stack.push(j);
+            }
+
+            let mut sum = vec![0; n];
+            for j in 0..n {
+                if previos_less_index[j] == -1 {
+                    sum[j] = heights[j] * (j as i32 + 1);
+                } else {
+                    sum[j] = sum[previos_less_index[j] as usize]
+                        + heights[j] * (j as i32 - previos_less_index[j] as i32);
+                }
+
+                result += sum[j];
+            }
+        }
+
+        result
+    }
+}