题目51

#include<stdio.h>#include<math.h>#include<stdlib.h>#include<string.h>int c[10005];int main(){int m;int x,y, i,q;int a,b;scanf("%d", &m);getchar();while(m--){q=0;memset(c, 0, sizeof(int)*10005);scanf("%d%d", &x,&y);getchar();while(y--){scanf("%d%d", &a,&b);getchar();for(;a<=b;a++){if(c[a] == 0)c[a] = 1;}}for(i=0;i<=x;i++){if(c[i] == 0)q++;}printf("%d\n", q);}return 0;}