Add solution #1582

Author: JoshCrozier

README.md

@@ -1,4 +1,4 @@
-# 1,382 LeetCode solutions in JavaScript
+# 1,383 LeetCode solutions in JavaScript
 
 [https://leetcodejavascript.com](https://leetcodejavascript.com)
 
@@ -1207,6 +1207,7 @@
 1577|[Number of Ways Where Square of Number Is Equal to Product of Two Numbers](./solutions/1577-number-of-ways-where-square-of-number-is-equal-to-product-of-two-numbers.js)|Medium|
 1578|[Minimum Time to Make Rope Colorful](./solutions/1578-minimum-time-to-make-rope-colorful.js)|Medium|
 1579|[Remove Max Number of Edges to Keep Graph Fully Traversable](./solutions/1579-remove-max-number-of-edges-to-keep-graph-fully-traversable.js)|Hard|
+1582|[Special Positions in a Binary Matrix](./solutions/1582-special-positions-in-a-binary-matrix.js)|Easy|
 1598|[Crawler Log Folder](./solutions/1598-crawler-log-folder.js)|Easy|
 1657|[Determine if Two Strings Are Close](./solutions/1657-determine-if-two-strings-are-close.js)|Medium|
 1668|[Maximum Repeating Substring](./solutions/1668-maximum-repeating-substring.js)|Easy|

solutions/1582-special-positions-in-a-binary-matrix.js

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+/**
+ * 1582. Special Positions in a Binary Matrix
+ * https://leetcode.com/problems/special-positions-in-a-binary-matrix/
+ * Difficulty: Easy
+ *
+ * Given an m x n binary matrix mat, return the number of special positions in mat.
+ *
+ * A position (i, j) is called special if mat[i][j] == 1 and all other elements in row i and
+ * column j are 0 (rows and columns are 0-indexed).
+ */
+
+/**
+ * @param {number[][]} mat
+ * @return {number}
+ */
+var numSpecial = function(mat) {
+  const rows = mat.length;
+  const cols = mat[0].length;
+  const rowSums = new Array(rows).fill(0);
+  const colSums = new Array(cols).fill(0);
+  let result = 0;
+
+  for (let i = 0; i < rows; i++) {
+    for (let j = 0; j < cols; j++) {
+      if (mat[i][j] === 1) {
+        rowSums[i]++;
+        colSums[j]++;
+      }
+    }
+  }
+
+  for (let i = 0; i < rows; i++) {
+    for (let j = 0; j < cols; j++) {
+      if (mat[i][j] === 1 && rowSums[i] === 1 && colSums[j] === 1) {
+        result++;
+      }
+    }
+  }
+
+  return result;
+};