POJ 2437 贪心+priority_queue

题意：



思路：

贪心 能不覆盖的就不盖

写得很乱 左闭右开的 temp

//By SiriusRen
#include <queue>
#include <cstdio>
#include <cstring>
#include <algorithm>
using namespace std;
int n,l,temp,ans;
struct Node{int from,to;}node[10050];
priority_queue<Node>pq;
bool operator < (Node a,Node b){
    return a.from>b.from;
}
int main(){
    scanf("%d%d",&n,&l);
    for(int i=1;i<=n;i++){
        scanf("%d%d",&node[i].from,&node[i].to),node[i].to--;
        pq.push(node[i]);
    }
    while(!pq.empty()){
        Node t=pq.top();pq.pop();
        if(temp<=t.from){
            int rec=(t.to-t.from+1)/l;
            ans+=rec;
            temp=t.from+l*rec;
            if(temp<=t.to)ans++,temp+=l;
        }
        else if(temp>t.to)
        {
            continue;
        }
        else{
            int rec=(t.to-temp+1)/l;
            ans+=rec;temp+=l*rec;
            if(temp<=t.to)ans++,temp+=l;
        }
    }
    printf("%d\n",ans);
}