Submission #870760

#	Time	Username	Problem	Language	Result	Execution time	Memory
870760		tuannm	Arranging Shoes (IOI19_shoes)	C++17	100 / 100	91 ms	24732 KiB

shoes

#include<bits/stdc++.h>
#define ii pair<int, int>
#define ll pair<long long, long long>
#define fi first
#define se second
#define pb push_back
using namespace std;
const int mod[2] = {1000000007, 998244353};
const int N = 2e5 + 1;
const string NAME = "";
const int lim = 2147483647;
//const unsigned int lim = 4294967295;
//const long long lim = 9223372036854775807;
//const unsigned long long lim = 18446744073709551615;
const int mset = 0x3f;
const double pi = acos(-1);
int n;
vector<int> q[2][N];
int perm[N];
long long tree[4 * N];
bool used[N];
 
void update(int s, int l, int r, int x, int y){
    if(x < l || x > r)
        return;
    if(l == r){
        tree[s] += y;
        return;
    }
    int mid = (l + r) / 2;
    update(2 * s, l, mid, x, y);
    update(2 * s + 1, mid + 1, r, x, y);
    tree[s] = tree[2 * s] + tree[2 * s + 1];
}
 
long long get(int s, int l, int r, int u, int v){
    if(l > v || r < u)
        return 0;
    if(l >= u && r <= v)
        return tree[s];
    int mid = (l + r) / 2;
    return get(2 * s, l, mid, u, v) + get(2 * s + 1, mid + 1, r, u, v);
}
 
long long count_swaps(vector<int> S){
  	n = S.size() / 2;
  	reverse(S.begin(), S.end());
  	S.pb(0);
  	reverse(S.begin(), S.end());
  	for(int i = 1; i <= 2 * n; ++i){
        if(S[i] > 0)
            q[1][S[i]].pb(i);
        else q[0][-S[i]].pb(i);
    }
    for(int i = 1; i <= n; ++i){
        reverse(q[0][i].begin(), q[0][i].end());
        reverse(q[1][i].begin(), q[1][i].end());
    }
 	int cnt = 0;
    for(int i = 1; i <= 2 * n; ++i){
        if(used[i])
            continue;
        if(S[i] > 0){
            int t0 = q[0][S[i]].back();
            int t1 = q[1][S[i]].back();
            q[1][S[i]].pop_back();
            q[0][S[i]].pop_back();
            used[t0] = true;
            used[t1] = true;
            perm[t0] = ++cnt;
            perm[t1] = ++cnt;
        }
        else{
            int t0 = q[0][-S[i]].back();
            int t1 = q[1][-S[i]].back();
            q[1][-S[i]].pop_back();
            q[0][-S[i]].pop_back();
            used[t0] = true;
            used[t1] = true;
            perm[t0] = ++cnt;
            perm[t1] = ++cnt;
        }
    }
    long long ans = 0;
    for(int i = 1; i <= 2 * n; ++i){
        ans += get(1, 1, 2 * n, perm[i] + 1, 2 * n);
        update(1, 1, 2 * n, perm[i], 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