Submission #1149145

#	Time	Username	Problem	Language	Result	Execution time	Memory
1149145		KawakiMeido	Election (BOI18_election)	C++20	0 / 100	2 ms	2368 KiB

election

/*Author: KawakiMeido*/
#include <bits/stdc++.h>
#define pb push_back
#define endl "\n"
#define ll long long
#define all(x) (x).begin(),(x).end()
#define pii pair<int,int>
#define fi first
#define se second

#define NAME "elections"

using namespace std;

/*Constants*/
const int N = 5e5+10;
const int INF = 1e9+7;
const long long LLINF = 1e18+3;

/*TestCases*/
int test=1;
void solve();
void TestCases(bool v){
    if (v) cin >> test;
    while(test--) solve();
}

vector<int> a(N);

struct Node{
    int t;
    int pre, suf;
    int mid;
    int ans;

    Node(){
        t = 0;
        pre = 0;
        suf = 0;
        mid = 0;
        ans = INF;
    }

    void DB(){
        cout << t << " ";
        cout << pre << " ";
        cout << suf << " ";
        cout << mid << " ";
        cout << ans << " ";
        cout << endl;
    }
};

Node Comb(Node x, Node y){
    if (x.ans == INF) return y;
    if (y.ans == INF) return x;
    Node res;

    res.ans = 0;

    res.t = x.t + y.t;

    res.pre = x.pre;
    res.suf = y.suf;

    int tpre = y.pre + y.mid;
    int tsuf = x.suf + x.mid;
    int mpre = 0;
    int msuf = 0;

    tpre = max(0,tpre + x.t);
    int deltapre = max(0,tpre - (x.pre+x.mid));
    if (deltapre < y.mid){
        res.mid+=deltapre;
        res.suf+=abs(y.mid - deltapre);
    }
    else{
        res.mid+=y.mid;
        mpre+=abs(deltapre - y.mid);
    }

//    if (deltapre < y.pre){
//        mpre+=abs(y.pre - deltapre);
//        res.suf+=y.mid;
//    }
//    else{
//        mpre+=y.pre;
//        res.mid+=abs(deltapre-y.pre);
//        res.suf+=abs(y.pre + y.mid - deltapre);
//    }

    tsuf = max(0,tsuf + y.t);
    int deltasuf = max(0,tsuf - (y.suf+y.mid));
    if (deltasuf < x.mid){
        res.mid+=deltasuf;
        res.pre+=abs(x.mid - deltasuf);
    }
    else{
        res.mid+=x.mid;
        msuf+=abs(deltasuf - x.mid);
    }


//    if (deltasuf < x.suf){
//        msuf+=abs(x.suf - deltasuf);
//        res.pre+=x.mid;
//    }
//    else{
//        msuf+=x.suf;
//        res.mid+=abs(deltasuf-x.suf);
//        res.pre+=abs(x.suf + x.mid - deltasuf);
//    }



    res.pre += mpre - min(mpre,msuf);
    res.suf += msuf - min(mpre,msuf);
    res.mid += min(mpre,msuf);
    res.ans += res.pre + res.suf + res.mid;

    return res;
}

struct SegTree{
    vector<Node> ST;
    int n;

    SegTree(){}

    void Build_Rec(int idx, int l, int r){
        if (l==r){
            ST[idx].t = a[l];
            if (a[l] == 1) ST[idx].mid = 1;
            else ST[idx].mid = 0;
            ST[idx].pre = 0;
            ST[idx].suf = 0;
            ST[idx].ans = ST[idx].mid;
        }
        else{
            int mid = (l+r)/2;
            Build_Rec(idx*2,l,mid);
            Build_Rec(idx*2+1,mid+1,r);
            ST[idx] = Comb(ST[idx*2],ST[idx*2+1]);
        }
//        cout << "Pos:" << idx << " [" << l << "," << r << "]" << endl;
//        ST[idx].DB();

    }

    void Build(int _n){
        n = _n;
        ST.resize(n*4+10);
        Build_Rec(1,1,n);
    }

    Node Query_Rec(int idx, int l, int r, int x, int y){
        if (r < x || y < l) return Node();
        if (x<=l && r<=y){
//            cout << "Pos:" << idx << " [" << l << "," << r << "]" << endl;
//            ST[idx].DB();
            return ST[idx];
        }
        int mid = (l+r)/2;
        return Comb(Query_Rec(idx*2,l,mid,x,y),Query_Rec(idx*2+1,mid+1,r,x,y));
//        Node tmp = Comb(Query_Rec(idx*2,l,mid,x,y),Query_Rec(idx*2+1,mid+1,r,x,y));
//        cout << "Pos:" << idx << " [" << l << "," << r << "]" << endl;
//        tmp.DB();
//        return tmp;
    }

    int Query(int l, int r){
        Node res = Query_Rec(1,1,n,l,r);
        return res.ans;
    }
} ST;

/*Global Variables*/
int n,q;

/*Solution*/
void solve(){
    cin >> n;
    for (int i=1; i<=n; i++){
        char c; cin >> c;
        if (c == 'C') a[i] = -1;
        else a[i] = 1;
    }

//    for (int i=1; i<=n; i++){
//        cout << a[i] << " ";
//    }
//    cout << endl;

//    ST.Build(n);
//
////    cout << "Query Section:" << endl;
//    cin >> q;
//    for (int i=1; i<=q; i++){
////        cout << "Q" << i << endl;
//        int l,r; cin >> l >> r;
//        cout << ST.Query(l,r) << endl;
//    }

}

/*Driver Code*/
signed main(){
    freopen(NAME".in","r",stdin);
    freopen(NAME".out","w",stdout);
    ios_base::sync_with_stdio(0);
    cin.tie(0);

    TestCases(0);

    return 0;
}

Compilation message (stderr)

election.cpp: In function 'int main()':
election.cpp:208:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  208 |     freopen(NAME".in","r",stdin);
      |     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~
election.cpp:209:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  209 |     freopen(NAME".out","w",stdout);
      |     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~

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