- chenxueze's blog
1107:校门外的树
- 2024-12-19 17:39:55 @
#include<bits/stdc++.h>
using namespace std;
int main()
{
int n,a,k1,k2,s[10001] = {},g = 0;
cin >> n >> a;
for (int i = 1;i <= a; i++) {
cin >> k1 >> k2;
for (int j = k1;j <= k2; j++) {
s[j] = 1;
}
}
for (int i = 0;i <= n; i++) {
if (s[i] == 0) {
g ++;
}
}
cout << g;
return 0;
}