Information
- ID
- 895
- Time
- 1000ms
- Memory
- 256MiB
- Difficulty
- 3
- Tags
- (None)
- # Submissions
- 142
- Accepted
- 48
- Uploaded By
#include<bits/stdc++.h>
using namespace std;
const int N=10010;
int a[N];
int main()
{
int L,m;
cin>>L>>m;
for(int i=1;i<=m;i++) //枚举区间个数
{
int l,r;
cin>>l>>r;
for(int j=l;j<=r;j++) //标记区间l到r之间的所有数
{
a[j]=1;
}
}
int c=0;
for(int i=0;i<=L;i++) //判断整个区间的每个位置
{
if(a[i]==0)
{
c++;
}
}
cout<<c;
return 0;
}