Create 2013-detect-squares.js

Author: everthis

2013-detect-squares.js

@@ -0,0 +1,80 @@
+
+var DetectSquares = function() {
+    this.xMap = new Map();
+    this.yMap = new Map();
+};
+
+/**
+ * @param {number[]} point
+ * @return {void}
+ */
+DetectSquares.prototype.add = function(point) {
+    const [ x, y ] = point;
+
+    // X-map
+    if (this.xMap.has(x)) {
+        const xMap = this.xMap.get(x);
+
+        if (xMap.has(y)) {
+            xMap.set(y, xMap.get(y) + 1);
+        } else {
+            xMap.set(y, 1);
+        }
+    } else {
+        const countMap = new Map();
+        countMap.set(y, 1);
+        this.xMap.set(x, countMap);
+    }
+
+    // Y-map
+    if (this.yMap.has(y)) {
+        const yMap = this.yMap.get(y);
+
+        if (yMap.has(x)) {
+            yMap.set(x, yMap.get(x) + 1);
+        } else {
+            yMap.set(x, 1);
+        }
+    } else {
+        const countMap = new Map();
+        countMap.set(x, 1);
+        this.yMap.set(y, countMap);
+    }
+};
+
+/**
+ * @param {number[]} point
+ * @return {number}
+ */
+DetectSquares.prototype.count = function(point) {
+    const [ x, y ] = point;
+    let ans = 0;
+
+    if (this.xMap.has(x) && this.yMap.has(y)) {
+        for (const y2 of this.xMap.get(x).keys()) {
+            if (y === y2) {
+                continue;
+            }
+
+            // Find parallel
+            const sideLen = Math.abs(y - y2);
+            const possibleX = [ x - sideLen, x + sideLen];
+
+            for (const px of possibleX) {
+                if (this.yMap.get(y).has(px) && this.xMap.has(px) && this.xMap.get(px).has(y2)) {
+                    ans += this.xMap.get(x).get(y2) * this.yMap.get(y).get(px)
+                        * this.xMap.get(px).get(y2);
+                }
+            }
+        }
+    }
+
+    return ans;
+};
+
+/** 
+ * Your DetectSquares object will be instantiated and called as such:
+ * var obj = new DetectSquares()
+ * obj.add(point)
+ * var param_2 = obj.count(point)
+ */