Submission #567577

#	Time	Username	Problem	Language	Result	Execution time	Memory
567577		Valaki2	Arranging Shoes (IOI19_shoes)	C++14	100 / 100	133 ms	14908 KiB

shoes

#include "shoes.h"
#include <bits/stdc++.h>
using namespace std;

#define int long long
#define pb push_back
#define mp make_pair

int n;
vector<int> val;
// diff[i] = value(i) - value(i - 1)
vector<int> segtree;

int range_query(int v, int vl, int vr, int ql, int qr) {
    if(ql > vr || qr < vl) {
        return 0;
    }
    if(vl == ql && vr == qr) {
        return segtree[v];
    }
    int mid = (vl + vr) / 2;
    return range_query(2 * v, vl, mid, ql, min(qr, mid))
            + range_query(2 * v + 1, mid + 1, vr, max(ql, mid + 1), qr);
}

int query(int pos) {
    return range_query(1, 1, 2 * n + 1, 1, pos);
}

void point_update(int v, int vl, int vr, int pos, int add) {
    if(vl == vr) {
        segtree[v] += add;
    } else {
        int mid = (vl + vr) / 2;
        if(pos <= mid) {
            point_update(2 * v, vl, mid, pos, add);
        } else {
            point_update(2 * v + 1, mid + 1, vr, pos, add);
        }
        segtree[v] = segtree[2 * v] + segtree[2 * v + 1];
    }
}

void update(int l, int r, int add) {
    point_update(1, 1, 2 * n + 1, l, add);
    point_update(1, 1, 2 * n + 1, r + 1, -add);
}

int value_of(int idx) {
    return idx + query(idx);
}

int solve() {
    int ans = 0;
    segtree.assign(1 + 4 * (2 * n + 1), 0);
    vector<int> nxt(1 + 2 * n, 0);
    vector<int> cur_pos(1 + n, -1);
    for(int i = 2 * n; i >= 1; i--) {
        if(val[i] > 0) {
            nxt[i] = cur_pos[val[i]];
            cur_pos[val[i]] = i;
        }
    }
    vector<int> pr(1 + 2 * n, 0);
    vector<bool> vis(1 + 2 * n, false);
    for(int i = 1; i <= 2 * n; i++) {
        if(val[i] < 0) {
            int &tmp = cur_pos[-val[i]];
            pr[i] = tmp;
            pr[tmp] = i;
            tmp = nxt[tmp];
        }
    }
    int cnt = 0;
    for(int i = 1; i <= 2 * n; i++) {
        if(!vis[i]) {
            int a = i, b = pr[i];
            if(val[a] > 0) {
                swap(a, b);
            }
            vis[a] = true;
            vis[b] = true;
            cnt++;
            ans += value_of(a) - (cnt * 2 - 1);
            update(1, a, 1);
            ans += value_of(b) - (cnt * 2);
            update(1, b, 1);
        }
    }
    return ans;
}

long long count_swaps(vector<signed> s) {
    n = s.size() / 2;
    val.pb(0);
    for(int i = 0; i < 2 * n; i++) {
        val.pb(s[i]);
    }
	return solve();
}

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