Submission #306033

#	Time	Username	Problem	Language	Result	Execution time	Memory
306033		talant117408	Arranging Shoes (IOI19_shoes)	C++17	100 / 100	259 ms	18928 KiB

shoes

#include "shoes.h"
#include <bits/stdc++.h>

using namespace std;

typedef long long ll;

const int N = 2e5+7;
ll tree[N*4], lz[N*4];

void push(int v, int l, int r){
    if(l > r) return;
    if(lz[v]){
        tree[v] += ll(r-l+1)*lz[v];
        if(l != r){
            lz[v<<1] += lz[v];
            lz[(v<<1)+1] += lz[v];
        }
        lz[v] = 0;
    }
}

ll get(int v, int l, int r, int ql, int qr){
    push(v, l, r);
    if(l > qr || r < ql) return 0;
    
    if(ql <= l && r <= qr) return tree[v];
    
    int mid = (l+r)>>1;
    return get(v<<1, l, mid, ql, qr)+get((v<<1)+1, mid+1, r, ql, qr);
}

void update(int v, int l, int r, int ql, int qr){
    push(v, l, r);
    if(l > qr || r < ql) return;
    
    if(ql <= l && r <= qr){
        tree[v] += ll(r-l+1);
        if(l != r){
            lz[v<<1]++;
            lz[(v<<1)+1]++;
        }
        return;
    }
    
    int mid = (l+r)>>1;
    update(v<<1, l, mid, ql, qr);
    update((v<<1)+1, mid+1, r, ql, qr);
    tree[v] = tree[v<<1]+tree[(v<<1)+1];
}
/*
ll count_swaps(vector <int> s);
int main() {
	int n;
	assert(1 == scanf("%d", &n));
	vector<int> S(2 * n);
	for (int i = 0; i < 2 * n; i++)
		assert(1 == scanf("%d", &S[i]));
	fclose(stdin);

	long long result = count_swaps(S);

	printf("%lld\n", result);
	fclose(stdout);
	return 0;
}
*/
ll count_swaps(vector<int> s){
    int n = s.size(), i;
    
    vector <pair <int, int>> order[N];
    for(i = 0; i < n; i++){
        order[abs(s[i])].emplace_back(make_pair(s[i], i+1));
    }
    
    ll ans = 0;
    vector <pair<int, int>> qu;
    
    for(i = 1; i <= n/2; i++){
        sort(order[abs(i)].begin(), order[abs(i)].end());
        for(int j = 0; j < (int)order[i].size()/2; j++){
            int l = order[i][j].second;
            int r = order[i][j+(int)order[i].size()/2].second;
            if(l > r){
                swap(l, r);
            }
            else{
                ans--;
            }
            qu.push_back(make_pair(l, r));
        }
    }
    
    sort(qu.begin(), qu.end());
    
    for(auto to : qu){
        int l = to.first, r = to.second;
        ans += (r+get(1, 1, n, r, r))-(l+get(1, 1, n, l, l));
        if(l+1 != r){
            update(1, 1, n, l+1, r-1);
        }
    }
    
    return ans;
}

• Subtask 1: 10 / 10
• Subtask 2: 20 / 20
• Subtask 3: 20 / 20
• Subtask 4: 15 / 15
• Subtask 5: 20 / 20
• Subtask 6: 15 / 15