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Nazi_ljx_weiren · 2024-11-30 11:49:53 · 休闲·娱乐

#include<iostream>
#include<string>
#include<map>
#include<algorithm>
#define int long long
using namespace std;
int n;
int m[20005], k[20005];
int endn = 0;
int beginn = 0;
int ans = 0;
signed main()
{
    cin >> n;
    for (int i = 0; i < n; i++)
    {
        cin >> m[i] >> k[i];
    }
    sort(m, m + n);
    sort(k, k + n);
    beginn = m[0];
    endn = k[0];
    for (int i = 0; i < n; i++)
    {

        if (k[i] > m[i + 1] && i != n - 1)
        {
            endn = k[i + 1];
        }
        else
        {
            ans += endn - beginn;
            beginn = m[i + 1];
            endn = k[i + 1];
        }
    }
    cout << ans;
    return 0;
}