poj 2437 Muddy roads

#include <stdio.h>#include <algorithm>using namespace std;const int MAXN=10010;struct Road{    int s;    int e;} road[MAXN];bool cmp(Road x, Road y){    return x.s<y.s;}int main(){    int n,l;    while (scanf("%d%d",&n,&l)!=EOF)    {        for (int i=0; i<n; i++) scanf("%d%d",&road[i].s,&road[i].e);        sort(road, road+n, cmp);        int ans=0;        int cnt=(road[0].e-road[0].s-1)/l+1;        ans+=cnt;        int pl=road[0].s+cnt*l;        for (int i=1; i<n; i++)        { if (pl>=road[i].e) continue; if (pl<road[i].s) pl=road[i].s; cnt=(road[i].e-pl-1)/l+1; ans+=cnt; pl+=cnt*l;        }        printf("%dn",ans);    }    return 0;}