85차 1번 문제풀이

Author: sangminlee98

live8/test85/문제1/이상민.js

@@ -0,0 +1,42 @@
+const input = require("fs")
+  .readFileSync(process.platform === "linux" ? "/dev/stdin" : "./input.txt")
+  .toString()
+  .trim()
+  .split("\n");
+
+const answer = [];
+const arr = [];
+
+for (let i = 2; i < input.length; i += 2) {
+  arr.push(input[i].split(" ").map(Number));
+}
+
+for (let i = 0; i < arr.length; i++) {
+  const tmp = arr[i].sort((a, b) => a - b);
+  const n = tmp.length;
+  let count = 0;
+
+  for (let j = 1; j < n - 1; j++) {
+    const mid = tmp[j];
+    let left = j - 1;
+    let right = j + 1;
+
+    while (left >= 0 && right < n) {
+      const leftDiff = mid - tmp[left];
+      const rightDiff = tmp[right] - mid;
+
+      if (leftDiff === rightDiff) {
+        count++;
+        left--;
+        right++;
+      } else if (leftDiff < rightDiff) {
+        left--;
+      } else {
+        right++;
+      }
+    }
+  }
+  answer.push(count);
+}
+
+console.log(answer.join("\n"));