#include<stdio.h>
#include<string.h>
#include<mem.h>
#include<cstring>
using namespace std;
int main()
{
??? int a[10010]= {0};
??? int sum=0;
??? int n,m,l,i,x,y;
??? scanf("%d",&n);
??? while(n--)
??? {
??????? scanf("%d%d",&l,&m);
??????? memset(a,0,sizeof(a));
??????? while(m--)
??????? {
??????????? scanf("%d%d",&x,&y);
??????????? for(i=x; i<=y; i++)
??????????? {
??????????????? a[i]=1;
??????????? }
??????? }
??????? for(i=0; i<=l; i++)
??????? {
??????????? if(a[i]==0)
??????????? {
??????????????? sum++;
??????????? }
??????? }
??????? printf("%d\n",sum);
??? }
??? return 0;
}

為什嗎第二次循環(huán)無法清零啊