大佬求助啊，第一个WA。。。

jh2023 @ 2023-08-07 17:29:14

#include <bits/stdc++.h>
using namespace std;
int f[100000];
int main() {
    int l, m;
    int a, b;
    cin >> l >> m;
    for (int i = 1; i <= l; i++) {
        f[i] = 1;
    }
    for (int i = 1; i <= m; i++) {
        cin >> a >> b;
        for (int j = a; j <= b; j++) {
            f[j] = 0;
        }
    }

    int total = 0;
    for (int i = 1; i <= l; i++) {
        total += f[i];
    }
    cout << total + 1;
    return 0;
}

by liu_le_chen @ 2023-08-07 17:47:48

#include <bits/stdc++.h>
using namespace std;
int f[100000];
int main() {
    int l, m;
    int a, b;
    cin >> l >> m;
    for (int i = 0; i <= l; i++) {
        f[i] = 1;
    }
    for (int i = 1; i <= m; i++) {
        cin >> a >> b;
        for (int j = a; j <= b; j++) {
            f[j] = 0;
        }
    }

    int total = 0;
    for (int i = 0; i <= l; i++) {
        total+=f[i];
    }
    cout << total;
    return 0;
}

by liu_le_chen @ 2023-08-07 17:49:10

注意审题，马路的开头是0，结尾时l