Submission #815750

#	Time	Username	Problem	Language	Result	Execution time	Memory
815750		exodus_	Ekoeko (COCI21_ekoeko)	C++14	20 / 110	48 ms	4616 KiB

Main

#include<bits/stdc++.h>
using namespace std;
const int N = 2e5+1;
int segtree[4*N] = {0};
int freq[30];
vector<char>urt;
deque<int>dex[30];
vector<int>isi;
void update(int idx, int low, int high, int val) {
    if(high==low && low==val) {
        segtree[idx]=1;
        return;
    }
    if(val<low || val>high) return;
    int mid=(low+high)/2;
    update(2*idx,low,mid,val);
    update(2*idx+1,mid+1,high,val);
    segtree[idx] = segtree[2*idx]+segtree[2*idx+1];
}
int quer(int idx, int low, int high, int l, int r) {
    if(low>=l && high<=r) {
        return segtree[idx];
    }
    if(low>r || high<l) return 0;
    int mid = (low+high)/2;
    int left = quer(2*idx,low,mid,l,r);
    int right = quer(2*idx+1,mid+1,high,l,r);
    return left+right;
}
int main() {
    int n;
    cin >> n;
    n*=2;
    string asli;
    cin >> asli;
    for(int i=0; i<n; i++) {
        freq[asli[i]-97]++;
    }
    for(int i=0; i<n; i++) {
        if(freq[asli[i]-97]>0) {
            urt.push_back(asli[i]);
            freq[asli[i]-97]-=2;
        }
    }
    int sizeurt=urt.size();
    for(int i=0; i<sizeurt; i++) {
        urt.push_back(urt[i]);
    }
    for(int i=0; i<n; i++) {
        dex[urt[i]-97].push_back(i);
    }
    for(int i=0; i<n; i++) {
        isi.push_back(dex[asli[i]-97].front());
        dex[asli[i]-97].pop_front();
    }
    int jwbn=0;
    for(int i=0; i<n; i++) {
        jwbn+=quer(1,0,n-1,isi[i]+1,n-1);
        update(1,0,n-1,isi[i]);
    }
    cout << jwbn << endl;
    return 0;
}

• Subtask 1: 0 / 10
• Subtask 2: 0 / 20
• Subtask 3: 0 / 20
• Subtask 4: 20 / 20
• Subtask 5: 0 / 40