feat: 1277. Count Square Submatrices with All Ones : DP

Author: upupming

Diff for: leetcode/残酷刷题/1277. Count Square Submatrices with All Ones.js

@@ -0,0 +1,18 @@
+/**
+ * @param {number[][]} matrix
+ * @return {number}
+ */
+const countSquares = function (matrix) {
+  const m = matrix.length; const n = matrix[0].length
+  const dp = [...Array(m)].map(() => [])
+  let ans = 0
+  for (let i = 0; i < m; i++) {
+    for (let j = 0; j < n; j++) {
+      if (matrix[i][j] === 1) {
+        dp[i][j] = Math.min(dp[i - 1]?.[j] ?? 0, dp[i]?.[j - 1] ?? 0, dp[i - 1]?.[j - 1] ?? 0) + 1
+        ans += dp[i][j]
+      } else { dp[i][j] = 0 }
+    }
+  }
+  return ans
+}

Diff for: leetcode/残酷刷题/README.md

@@ -68,6 +68,7 @@
 - 1751. Maximum Number of Events That Can Be Attended II
 - 1478. Allocate Mailboxes
     - DP + 货仓选址
+- 1277. Count Square Submatrices with All Ones
 
 #### 状态压缩