Submission #938160

#	Time	Username	Problem	Language	Result	Execution time	Memory
938160		LittleOrange	Growing Vegetable is Fun 3 (JOI19_ho_t3)	C++17	0 / 100	1 ms	348 KiB

joi2019_ho_t3

#include<bits/stdc++.h>
using namespace std;
using ll = long long;
struct BIT{
    ll n;
    vector<ll> a;
    BIT(ll N):n(N),a(N+1){}
    void add(ll i, ll x){
        for(;i<=n;i+=i&-i) a[i] += x;
    }
    ll get(ll i){
        ll x = 0;
        for(;i;i-=i&-i) x +=a[i];
        return x;
    }
};
int main(){
    ios::sync_with_stdio(0);cin.tie(0);
    ll n;
    string s;
    cin >> n >> s;
    vector<ll> cnt(3,0);
    vector<ll> a(n);
    for(ll i = 0;i<n;i++) {
        a[i] = s[i]=='R'?0:s[i]=='G'?1:2;
        cnt[a[i]]++;
    }
    vector<ll> b(n);
    iota(b.begin(),b.end(),1);
    ll ans = 0;
    for(ll i = 1;i<n-1;i++){
        if(s[i]==s[i-1]){
            ll j = i+1;
            while(s[j]==s[i]&&j<n-1) j++;
            for(ll k = j;k>i;k--) swap(s[k],s[k-1]);
            for(ll k = j;k>i;k--) swap(b[k],b[k-1]);
        }
    }
    for(ll i = n-2;i>0;i--){
        if(s[i]==s[i+1]){
            ll j = i-1;
            while(s[j]==s[i]&&j>0) j--;
            for(ll k = j;k<i;k++) swap(s[k],s[k+1]);
            for(ll k = j;k<i;k++) swap(b[k],b[k+1]);
        }
    }
    for(ll i = 1;i<n;i++){
        if(s[i]==s[i-1]){
            cout << "-1\n";
            return 0;
        }
    }
    BIT t(n);
    for(ll i = n-1;i>=0;i--){
        ans += t.get(b[i]);
        t.add(b[i],1);
    }
    cout << ans << "\n";
}

• Subtask 1: 0 / 5
• Subtask 2: 0 / 55
• Subtask 3: 0 / 15
• Subtask 4: 0 / 25