HDU3145 Max Sum of Max-K-sub-sequence (单调队列模板)

#include<iostream>
#include<queue>
#include<map>
#include<vector>
#include<cstdio>
#include<algorithm>
#include<stack>
#include<cstring>
using namespace std;
typedef long long ll;
const int N=2e6+7;
const int inf=0x3f3f3f3f;
int a[N];
int q[N];
int s[N];
int main(){
    int t;
    cin>>t;
    while(t--){
    int n,k;
    cin>>n>>k;
    int i,j;
    memset(s,0,sizeof s);
    for(i=1;i<=n;i++){
        scanf("%d",&a[i]);
        s[i]=s[i+n]=a[i];
    }
    for(i=1;i<=2*n;i++)
        s[i]+=s[i-1];
    int hh=0;
    int tt=0;
    q[0]=0;
    int res=-0x3f3f3f3f;
    int pos=0;
    int ed=0;
    for(i=1;i<=2*n;i++){
        while(hh<=tt&&q[hh]<i-k)
            hh++;
        if(s[i]-s[q[hh]]>res){
            res=s[i]-s[q[hh]];
            pos=q[hh]+1;
            ed=i;
        }
        else if(s[i]-s[q[hh]]==res){
            if(pos>q[hh]+1){
                pos=q[hh]+1;
                ed=i;
            }
            else if(pos==q[hh]+1){
                if(i<ed)
                ed=i;
            }
        }
        while(hh<=tt&&s[q[tt]]>=s[i])
            tt--;
        q[++tt]=i;
    }
    if(ed>n)
        ed-=n;
    cout<<res<<" "<<pos<<" "<<ed<<endl;
    }

}