BOJ_2473 : 세 용액

Author: spring0913

week4/BOJ_2473(세 용액).java

@@ -0,0 +1,49 @@
+import java.io.*;
+import java.util.*;
+
+public class Main {
+
+    public static void main(String[] args) throws IOException {
+        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
+        int N = Integer.parseInt(br.readLine());
+        StringTokenizer st = new StringTokenizer(br.readLine());
+        long[] arr = new long[N];
+        for (int i = 0; i < N; i++) {
+            arr[i] = Long.parseLong(st.nextToken());
+        }
+        Arrays.sort(arr);
+        long minAbs = Math.abs(arr[0] + arr[1] + arr[2]);
+        long[] answer = new long[]{arr[0], arr[1], arr[2]};
+        for (int i = 0; i < N - 2; i++) {
+            long[] result = twoPointer(arr, i);
+            long resultAbs = Math.abs(result[0] + result[1] + result[2]);
+            if (minAbs > resultAbs) {
+                minAbs = resultAbs;
+                answer = result.clone();
+            }
+        }
+        System.out.println(answer[0] + " " + answer[1] + " " + answer[2]);
+    }
+
+    public static long[] twoPointer(long[] arr, int index) {
+        int left = index + 1;
+        int right = arr.length - 1;
+        int leftIndex = left;
+        int rightIndex = right;
+        long minAbs = Math.abs(arr[left] + arr[right] + arr[index]);
+        while (left < right) {
+            long sum = arr[index] + arr[left] + arr[right];
+            if (minAbs > Math.abs(sum)) {
+                minAbs = Math.abs(sum);
+                leftIndex = left;
+                rightIndex = right;
+            }
+            if (sum > 0) {
+                right--;
+            } else {
+                left++;
+            }
+        }
+        return new long[]{arr[index], arr[leftIndex], arr[rightIndex]};
+    }
+}