115차 1번 문제풀이

Author: jinoo0306

live11/test115/문제1/조진우.js

@@ -0,0 +1,42 @@
+const input = require("fs")
+  .readFileSync(
+    process.platform === "linux"
+      ? "/dev/stdin"
+      : require("path").join(__dirname, "input.txt"),
+    "utf8"
+  )
+  .trim()
+  .split("\n")
+  .map(Number);
+
+function solution(input) {
+  const arr = input.slice(1);
+  let answer = 0;
+
+  function dfs(start, end) {
+    if (start > end) return null;
+    if (start === end) return arr[start];
+
+    let max = -Infinity;
+    let maxIdx = -1;
+    for (let i = start; i <= end; i++) {
+      if (arr[i] > max) {
+        max = arr[i];
+        maxIdx = i;
+      }
+    }
+
+    const leftMax = dfs(start, maxIdx - 1);
+    const rightMax = dfs(maxIdx + 1, end);
+
+    if (leftMax !== null) answer += max - leftMax;
+    if (rightMax !== null) answer += max - rightMax;
+
+    return max;
+  }
+
+  dfs(0, arr.length - 1);
+  return answer;
+}
+
+console.log(solution(input));