백준 17390번 이건 꼭 풀어야 해! C++

https://www.acmicpc.net/problem/17390

17390번: 이건 꼭 풀어야 해!

 

정렬 후 누적합을 구해서 풀었다.

 

#include <iostream>
#include <string>
#include <vector>
#include <math.h>
#include <algorithm>
#include <utility>
#include <stack>
#include <queue>
#include <math.h>
#include <set>
#include <map>
#include <list>
#include <unordered_map>
#include <unordered_set>
#include <iomanip>
#include <limits.h>

using namespace std;
using int64 = long long;

int n, q;
vector<int> v;
vector<int64> accSum;

int main() {
    ios_base::sync_with_stdio(false);
    cin.tie(NULL);
    cout.tie(NULL);

    cin >> n >> q;
    v = vector<int>(n);
    accSum = vector<int64>(n, 0);
    for (int i = 0; i < n; i++) cin >> v[i];
    sort(v.begin(), v.end());
    accSum[0] = v[0];
    for (int i = 1; i < n; i++) {
        accSum[i] = accSum[i - 1] + v[i];
    }
    for (int i = 0; i < q; i++) {
        int s, e;
        cin >> s >> e;
        s -= 1;
        e -= 1;
        int64 ans = 0;
        if (s == 0) ans = accSum[e];
        else ans = accSum[e] - accSum[s - 1];
        cout << ans << "\n";
    }
}