#include<stdio.h>
int tree[100000],area[101][2];
int main()
{
int road,i,x,j,sum=0;
scanf("%d %d",&road,&x);
for(i=0;i<x;i++)
scanf("%d %d",&area[i][0],&area[i][1]);
for(i=0;i<10000;i++)
tree[i]=1;
for(i=0;i<=road;i++)
for(j=0;j<x;j++)
{
if((area[j][0]<=i)&&(area[j][1]>=i))
tree[i]=0;
}
for(i=0;i<=road;i++)
{
sum+=tree[i];
}
printf("%d\n",sum);
return 0;
}
by liushishiguang @ 2019-03-01 13:09:02
## @[liushishiguang](/space/show?uid=183707) 希望更丰富的展现？使用[Markdown](https://www.luogu.org/wiki/show?name=%E5%B8%AE%E5%8A%A9%EF%BC%9Amarkdown)
by mcyqwq @ 2019-03-01 13:10:04
@[__CZK__](/space/show?uid=121908) 只会C语言啊
by liushishiguang @ 2019-03-01 13:11:50
高能预警：大佬出来啦
by mcyqwq @ 2019-03-01 13:14:35
初始化tree数组的时候加一个<=10000
by wen_chang @ 2019-03-01 13:14:36
诶说错了，是把<10000改成<=10000
by wen_chang @ 2019-03-01 13:15:30
@[liushishiguang](/space/show?uid=183707)
by wen_chang @ 2019-03-01 13:15:40
@[yjs2006](/space/show?uid=117142) 我试试
by liushishiguang @ 2019-03-01 13:17:39
@[yjs2006](/space/show?uid=117142) 竟然通过了，我可以请问一下，为什么吗
by liushishiguang @ 2019-03-01 13:19:03
高能预警：大佬准备再次出现
by mcyqwq @ 2019-03-01 13:21:22