Submission #1050082

#	Time	Username	Problem	Language	Result	Execution time	Memory
1050082		matere	Election (BOI18_election)	C++14	0 / 100	28 ms	160616 KiB

election

#include<bits/stdc++.h>
using namespace std;
int a[500005],pref[500005],suf[500005],lg[500005];
pair<int,int>spp[500005][20],sps[500005][20];
vector<int>v;
int main(){
    int n;
    char c;
    cin>>n;
    for(int i=2;i<=500004;i++) lg[i]=lg[i/2]+1;
    for(int i=1;i<=500004;i++) spp[i][0].first=sps[i][0].first=1e9;
    v.push_back(0);
    for(int i=1;i<=n;i++){
        cin>>c;
        if(c=='T') v.push_back(i);
        a[i]=(c=='C')*2-1;
        pref[i]=pref[i-1]+a[i];
        spp[i][0].first=pref[i];
        spp[i][0].second=i;
    }
    v.push_back(n+1);
    for(int i=n;i>=1;i--){
        suf[i]=suf[i+1]+a[i];
        sps[i][0].first=suf[i];
        sps[i][0].second=i;
    }
    for(int pr=1;pr<=19;pr++){
        for(int i=1;i<=n;i++){
            spp[i][pr].second=spp[i][pr-1].second;
            sps[i][pr].second=sps[i][pr-1].second;
            if(spp[i][pr-1].first>spp[min(n,i+(1<<(pr-1)))][pr-1].first) spp[i][pr].second=spp[min(n,i+(1<<(pr-1)))][pr-1].second;
            if(sps[i][pr-1].first>sps[min(n,i+(1<<(pr-1)))][pr-1].first) sps[i][pr].second=sps[min(n,i+(1<<(pr-1)))][pr-1].second;
            spp[i][pr].first=min(spp[i][pr-1].first,spp[min(n,i+(1<<(pr-1)))][pr-1].first);
            sps[i][pr].first=min(sps[i][pr-1].first,sps[min(n,i+(1<<(pr-1)))][pr-1].first);
        }
    }
    int q;
    cin>>q;
    for(int i=1;i<=q;i++){
        int l,r;
        cin>>l>>r;
        int mn1=min(spp[l][lg[r-l+1]].first,spp[r-(1<<lg[r-l+1])+1][lg[r-l+1]].first);
        int mn1i=spp[l][lg[r-l+1]].second;
        if(spp[l][lg[r-l+1]].first>spp[r-(1<<lg[r-l+1])+1][lg[r-l+1]].first) mn1i=spp[r-(1<<lg[r-l+1])+1][lg[r-l+1]].second;
        int mn2=min(sps[l][lg[r-l+1]].first,sps[r-(1<<lg[r-l+1])+1][lg[r-l+1]].first);
        int mn2i=sps[l][lg[r-l+1]].second;
        if(sps[l][lg[r-l+1]].first>sps[r-(1<<lg[r-l+1])+1][lg[r-l+1]].first) mn2i=sps[r-(1<<lg[r-l+1])+1][lg[r-l+1]].second;
        mn1-=pref[l-1];
        mn2-=suf[r+1];
        mn1=min(mn1,0);
        mn2=min(mn2,0);
        cout<<max(-mn1,max(-mn2,-mn1-mn2-((int)(upper_bound(v.begin(),v.end(),mn1i)-v.begin())-(int)(lower_bound(v.begin(),v.end(),mn2i)-v.begin()))))<<endl;
    }
}

• Subtask 1: 0 / 28
• Subtask 2: 0 / 54
• Subtask 3: 0 / 18