LC 1277. Count Square Submatrices with All Ones (Rust)

Author: raul-sauco

README.md

@@ -498,6 +498,7 @@ to the solution in this repository.
 | [1266. Minimum Time Visiting All Points][lc1266]                                              | 🟢 Easy    | [![rust](res/rs.png)][lc1266rs]                                                                       |
 | [1268. Search Suggestions System][lc1268]                                                     | 🟠 Medium  | [![python](res/py.png)][lc1268py]                                                                     |
 | [1269. Number of Ways to Stay in the Same Place After Some Steps][lc1269]                     | 🟠 Medium  | [![rust](res/rs.png)][lc1269rs]                                                                       |
+| [1277. Count Square Submatrices with All Ones][lc1277]                                        | 🟠 Medium  | [![rust](res/rs.png)][lc1277rs]                                                                       |
 | [1282. Group the People Given the Group Size They Belong To][lc1282]                          | 🟠 Medium  | [![rust](res/rs.png)][lc1282rs]                                                                       |
 | [1289. Minimum Falling Path Sum II][lc1289]                                                   | 🔴 Hard    | [![rust](res/rs.png)][lc1289rs]                                                                       |
 | [1291. Sequential Digits][lc1291]                                                             | 🟠 Medium  | [![rust](res/rs.png)][lc1291rs]                                                                       |
@@ -1872,6 +1873,8 @@ to the solution in this repository.
 [lc1268py]: leetcode/search-suggestions-system.py
 [lc1269]: https://leetcode.com/problems/number-of-ways-to-stay-in-the-same-place-after-some-steps/
 [lc1269rs]: leetcode/number-of-ways-to-stay-in-the-same-place-after-some-steps.rs
+[lc1277]: https://leetcode.com/problems/count-square-submatrices-with-all-ones/
+[lc1277rs]: leetcode/count-square-submatrices-with-all-ones.rs
 [lc1282]: https://leetcode.com/problems/group-the-people-given-the-group-size-they-belong-to/
 [lc1282rs]: leetcode/group-the-people-given-the-group-size-they-belong-to/
 [lc1289]: https://leetcode.com/problems/minimum-falling-path-sum-ii/

leetcode/count-square-submatrices-with-all-ones.rs

@@ -0,0 +1,75 @@
+// 1277. Count Square Submatrices with All Ones
+// 🟠 Medium
+//
+// https://leetcode.com/problems/count-square-submatrices-with-all-ones/
+//
+// Tags: Array - Dynamic Programming - Matrix
+
+struct Solution;
+impl Solution {
+    /// Use dynamic programming, visit all cells, for each cell that contains a 1, check the number
+    /// of squares that finish on that cell using the number of squares that finish in its 3
+    /// neighbors to the left, top and top-left, and add that to the result.
+    ///
+    /// Time complexity: O(m*n) - We visit each cell in the matrix and check 3 other cells for
+    /// each cell that we visit.
+    /// Space complexity: O(1) - Since we are taking ownership of the matrix, we can decide if we
+    /// want to mutate it, the caller does not have access to matrix after calling.
+    ///
+    /// Runtime 3 ms Beats 100%
+    /// Memory 2.80 MB Beats 66%
+    pub fn count_squares(mut matrix: Vec<Vec<i32>>) -> i32 {
+        let mut res = 0;
+        for r in 0..matrix.len() {
+            for c in 0..matrix[0].len() {
+                if matrix[r][c] == 1 {
+                    if r == 0 || c == 0 {
+                        matrix[r][c] = 1;
+                    } else {
+                        matrix[r][c] = 1 + matrix[r - 1][c]
+                            .min(matrix[r][c - 1])
+                            .min(matrix[r - 1][c - 1]);
+                    }
+                    res += matrix[r][c];
+                }
+            }
+        }
+        res
+    }
+}
+
+// Tests.
+fn main() {
+    let tests = [
+        (
+            vec![vec![0, 1, 1, 1], vec![1, 1, 1, 1], vec![0, 1, 1, 1]],
+            15,
+        ),
+        (vec![vec![1, 0, 1], vec![1, 1, 0], vec![1, 1, 0]], 7),
+    ];
+    println!("\n\x1b[92m» Running {} tests...\x1b[0m", tests.len());
+    let mut success = 0;
+    for (i, t) in tests.iter().enumerate() {
+        let res = Solution::count_squares(t.0.clone());
+        if res == t.1 {
+            success += 1;
+            println!("\x1b[92m✔\x1b[95m Test {} passed!\x1b[0m", i);
+        } else {
+            println!(
+                "\x1b[31mx\x1b[95m Test {} failed expected: {:?} but got {}!!\x1b[0m",
+                i, t.1, res
+            );
+        }
+    }
+    println!();
+    if success == tests.len() {
+        println!("\x1b[30;42m✔ All tests passed!\x1b[0m")
+    } else if success == 0 {
+        println!("\x1b[31mx \x1b[41;37mAll tests failed!\x1b[0m")
+    } else {
+        println!(
+            "\x1b[31mx\x1b[95m {} tests failed!\x1b[0m",
+            tests.len() - success
+        )
+    }
+}