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백준 2437 풀이 및 해설

너무 좋은 블로그 풀이를 발견했다!

수직선으로 범위를 파악해서 그 범위가 끊이지 않는지 파악하는 것이 핵심이었다.

누적합 문제를 풀 때 다음 아이디어를 기억하자 :0

Python Solution

import sys
n = int(sys.stdin.readline())
weight = [0]
weight.extend(list(map(int, sys.stdin.readline().split())))
weight.sort()

temp = 0
arr = []
for i in range(len(weight)):
    temp += weight[i]
    arr.append(temp)

flag = False
for i in range(1, len(weight)):
    if arr[i-1] + 1 < weight[i]:
        print(arr[i-1] + 1)
        flag = True
        break

if flag == False:
    print(arr[-1]+1)

import sys
n = int(sys.stdin.readline())
weight = (list(map(int, sys.stdin.readline().split())))
weight.sort()

target = 1
for i in weight:
    if target < i:
        break
    target += i

print(target)

Java Solution

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.util.Arrays;
import java.util.StringTokenizer;

public class Main {

    static int n;
    static int[] weight;
    static int target;

    public static void main(String[] args) throws IOException {
        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
        n = Integer.parseInt(br.readLine());
        StringTokenizer st = new StringTokenizer(br.readLine());

        weight = new int[n];
        for (int i=0; i<n; i++){
            weight[i] = Integer.parseInt(st.nextToken());
        }

//        System.out.println(n);
//        System.out.println(Arrays.toString(weight));

        Arrays.sort(weight);

        target = 1;
        for (int i=0; i<n; i++) {
            if (target < weight[i]) {
                break;
            }
            target += weight[i];
        }

        System.out.println(target);
    }
}

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.util.Arrays;

public class Main {

    static int n;
    static int[] weight;
    static int target;

    public static void main(String[] args) throws IOException {
        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
        n = Integer.parseInt(br.readLine());

        weight = Arrays.stream(br.readLine().split(" ")).mapToInt(Integer::parseInt).sorted().toArray();

//        System.out.println(Arrays.toString(weight));

        target = 1;

        target = Arrays.stream(weight)
                // takewhile: if문 -> 아닐경우 반복작업 중단
                .takeWhile(w -> target >= w)
                // 초깃값, 누적된 값, 현재 요소
                .reduce(target, (acc, w) -> target += w);

        System.out.println(target);

    }
}