1727. 重新排列后的最大子矩阵

src/main.rs

@@ -1,58 +1,35 @@
+use std::cmp::max;
+
 struct Solution;
 mod arr;
 impl Solution {
-    fn get_count(grid: &Vec<Vec<i32>>, x: usize, y: usize, i: usize) -> i32 {
-        if i == 0 {
-            return grid[y][x];
-        }
-        let mut cnt = 0;
-
-        for t in 0..i {
-            cnt += grid[y + t][x + t];
-            cnt += grid[y + i + t][x + i - t];
-            cnt += grid[y + 2 * i - t][x - t];
-            cnt += grid[y + i - t][x - i + t];
-        }
-        cnt
-    }
-    pub fn get_biggest_three(grid: Vec<Vec<i32>>) -> Vec<i32> {
-        let (mut m1, mut m2, mut m3) = (0, 0, 0);
-
-        for i in 0..grid.len() {
-            let path = i * 2 + 1;
-            if path > grid.len() || path > grid[0].len() {
-                break;
-            }
-            for j in i..grid[0].len() - i {
-                for k in 0..grid.len() - 2 * i {
-                    let cnt = Solution::get_count(&grid, j, k, i);
-                    if cnt == m1 || cnt == m2 || cnt == m3 {
-                        continue;
-                    }
-                    if cnt > m1 {
-                        (m1, m2, m3) = (cnt, m1, m2);
-                    } else if cnt > m2 {
-                        (m2, m3) = (cnt, m2);
-                    } else if cnt > m3 {
-                        m3 = cnt;
+    pub fn largest_submatrix(mut matrix: Vec<Vec<i32>>) -> i32 {
+        for i in 1..matrix.len() {
+            for j in 0..matrix[i].len() {
+                if matrix[i][j] == 1 {
+                    matrix[i][j] = 1 + matrix[i - 1][j];
                 }
             }
         }
+        let mut ans = 0;
+        let mut arr = Vec::with_capacity(matrix[0].len());
+        for i in 0..matrix.len() {
+            for j in 0..matrix[i].len() {
+                arr.push(matrix[i][j]);
             }
-        let mut ret = vec![m1];
-        if m2 != 0 {
-            ret.push(m2);
-            if m3 != 0 {
-                ret.push(m3);
+            arr.sort_unstable_by(|a, b| b.cmp(a));
+            for j in 0..matrix[i].len() {
+                ans = max(ans, arr[j] * (j + 1) as i32);
             }
+            arr.clear()
         }
-        ret
+        ans
     }
 }
 
 fn main() {
-    let result = Solution::get_biggest_three(arr::make_matrix(
-        "[[6,7,7,7,7]]",
+    let result = Solution::largest_submatrix(arr::make_matrix(
+        "[[0,0,1],[1,1,1],[1,0,1]]",
     ));
     println!("{:?}", result);
 }