Submission #510135

#	Time	Username	Problem	Language	Result	Execution time	Memory
510135		ETK	Swap Swap Sort (CCO21_day1problem1)	C++14	0 / 25	156 ms	19048 KiB

Main

#include <bits/stdc++.h>
#define rep(i,a,b) for(int i=(a);i<=(b);++i)
#define per(i,a,b) for(int i=(a);i>=(b);--i)
#define pii pair<int,int>
#define vi vector<int>
#define mp make_pair
#define fi first
#define se second
#define pb push_back
#define debug(...) fprintf(stderr, __VA_ARGS__)
#define ALL(x) x.begin(),x.end()
#define sz(x) int(x.size())
#define ll long long
using namespace std;
inline ll read(){
    ll x=0,f=1;char ch=getchar();
    while (!isdigit(ch)){if (ch=='-') f=-1;ch=getchar();}
    while (isdigit(ch)){x=x*10+ch-48;ch=getchar();}
    return x*f;
}
const int N=1e5+5,B = 100;
int n,k,q,id[N],a[N],idx[N],cnt;
int t[N];
void add(int x,int v){for(;x <= n;x += x & -x)t[x] += v;}
ll Q(int x){
    ll res = 0;
    for(;x;x -= x & -x)res += t[x];
    return res;
}
vector <int> pos[N];
vector <ll> pre[N];
ll work(int a,int b){
    ll tot = (ll)sz(pos[a]) * sz(pos[b]);
    if(sz(pos[a]) > B)return pre[b][idx[a]];
    if(sz(pos[b]) > B)return tot - pre[a][idx[b]];
    int j = 0;
    ll res = 0;
    for(auto x : pos[a]){
        while(j < sz(pos[b]) && pos[b][j] < x)j++;
        res += j;
    }
    return res;
}
int main(){
    n = read(),k = read(),q = read();
    rep(i,1,n){
        a[i] = read();
        pos[a[i]].pb(i);
    }
    rep(i,1,n)id[i] = i;
    ll ans = 0;
    rep(i,1,n){
        ans += Q(k) - Q(a[i]);
        add(a[i],1);
    }
    rep(i,1,k)if(sz(pos[i]) > B){
        idx[i] = cnt++;
        rep(j,1,k)pre[j].pb(0);
        int res = 0;
        rep(j,1,n){
            if(a[j] == i)res++;
            else pre[a[j]].back() += res;
        }
    }
    while(q--){
        int x = read();
        ans += (ll)sz(pos[id[x]]) * sz(pos[id[x+1]]) - 2 * work(id[x],id[x+1]);
        printf("%lld\n",ans);
        swap(id[x],id[x+1]);
    }
    return 0;
}

• Subtask 1: 0 / 3
• Subtask 2: 0 / 3
• Subtask 3: 0 / 5
• Subtask 4: 0 / 14