http://icpc.upc.edu.cn/problem.php?cid=1721&pid=6
#include<cstdio>
#include<cstring>
using namespace std;
int n,d,i,j,k,kk,k1,l,r,a[10001],b[10001],c[10001];
int main()
{
scanf("%d%d",&n,&d);
for (i=1; i<=d; i++)
{
scanf("%d%d",&l,&r);
for (j=l; j<=r; j++)
{
a[j]=1;
}
k=1;
kk=0;
while (k<=n)
{
if (a[k])
{
k1=k+1;
while (a[k1])
{
k1++;
}
kk++;
b[kk]=k;
c[kk]=k1-1;
k=k1;
}
else
while (a[k]==0) k++;
}
for (int ii=1;ii<kk;ii++){
printf("[%d,%d],",b[ii],c[ii]);
}
printf("[%d,%d]\n",b[kk],c[kk]);
}
}