Submission #1096802

#	Time	Username	Problem	Language	Result	Execution time	Memory
1096802		vjudge1	Election (BOI18_election)	C++17	0 / 100	16 ms	31836 KiB

election

#include<bits/stdc++.h>
using namespace std;

#define ll long long

typedef pair<int,int> pii;
typedef pair<int,pii> pip;
typedef pair<pii,int> ppi;
#define f first
#define s second

#define all(x) x.begin(),x.end()
#define unicorn(x) x.resize(unique(x.begin(),x.end())-x.begin())

#define pb(x) push_back(x);
#define pp() pop_back();

const int L = 5e5+10, inf = 1e9;
int n;
int vote[L],ps[L],ss[L],tps[L],tss[L];
int gr[L];
vector<pii> sec;

random_device device;
default_random_engine rng(device());
#define randt(a,b) uniform_int_distribution<int64_t>(a,b)(rng)

void pr(int* vv,int l,int r){for(int i=l;i<r;i++){cout<<vv[i]<<" ";}cout<<endl;}
void prv(vector<int> vv){for(auto i:vv){cout<<i<<" ";}cout<<endl;}
void prl(long long* vv,int l,int r){for(int i=l;i<r;i++){cout<<vv[i]<<" ";}cout<<endl;}
void prvl(vector<long long> vv){for(auto i:vv){cout<<i<<" ";}cout<<endl;}
void prp(pii* vv,int l,int r){for(int i=l;i<r;i++){cout<<i<<": "<<vv[i].f<<" , "<<vv[i].s<<" / ";}cout<<endl;}

struct sagi{
    struct node{
        pii mn;
        node(){
            mn = pii(inf,inf);
        }
    }t[L<<2];

    void build(int id,int l,int r,int* a){
        if(l+1 == r){
            t[id].mn = pii(a[l],l);
            return;
        }
        int mid = (l+r)>>1;
        build(2*id+0,l,mid,a);
        build(2*id+1,mid,r,a);
        t[id].mn = min(t[2*id+0].mn,t[2*id+1].mn);
    }

    pii get(int id,int l,int r,int l2,int r2){
        if(l==l2 and r==r2){
            return t[id].mn;
        }
        int mid = (l2+r2)>>1;
        pii ans = pii(inf,inf);
        if(l<mid)
            ans = min(ans, get(2*id+0,l,min(r,mid),l2,mid));
        if(r>mid)
            ans = min(ans, get(2*id+1,max(l,mid),r,mid,r2));
        return ans;
    }
}pseg,sseg;

int z(int a){
    if(a < 0)
        return 0;
    return a;
}

int main(){
    //ofstream cout ("out.txt");
    //ifstream cin ("in.txt");

    ios_base::sync_with_stdio(false);
    cin.tie(0);
    cout.tie(0);
    cin>>n;
    map<char,int> inpc;
    inpc['C'] = 1;
    inpc['T'] = -1;
    for(int i=1;i<=n;i++){
        char inp;
        cin>>inp;
        vote[i] = inpc[inp];
    }

    ps[0] = ss[n+1] = 0;
    for(int i=1;i<=n;i++){
        ps[i] = ps[i-1] + vote[i];
    }
    for(int i=n;i>=1;i--){
        ss[i] = ss[i+1] + vote[i];
    }

    int st = 10;
    for(int i=1;i<=n;i++){
        if(vote[i] != st){
            sec.pb(pii(i,i));
            st = vote[i];
            gr[i] = sec.size()-1;
        }
        else{
            sec.back().s++;
            gr[i] = sec.size()-1;
        }
    }

    pseg.build(1,1,n+1,ps);
    sseg.build(1,1,n+1,ss);

    int q;
    cin>>q;
    for(int tt=0;tt<q;tt++){
        int l,r;
        cin>>l>>r;
        pii db = pseg.get(1,l,r+1,1,n+1);
        pii df = sseg.get(1,l,r+1,1,n+1);
        db.f -= ps[l-1];
        df.f -= ss[r+1];
        db.f = z(-db.f);
        df.f = z(-df.f);
        if(gr[db.s] == gr[df.s]){
            pii rg = sec[gr[db.s]];
            db.f -= min(z(db.f-(tps[rg.f-1]-tps[l-1])),z(df.f-(tss[rg.s-1]-tss[r+1])));
        }
        cout<<z(db.f+df.f)<<endl;
    }
}

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