Submission #485813

#	Time	Username	Problem	Language	Result	Execution time	Memory
485813		qwerasdfzxcl	Arranging Shoes (IOI19_shoes)	C++14	45 / 100	64 ms	9664 KiB

shoes

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

using namespace std;
typedef long long ll;
vector<int> pos[100100];
struct Seg{
    int tree[400400], sz;
    void init(int n) {sz = n;}
    void update(int p){for(tree[p+=sz]++;p>1;p>>=1) tree[p>>1]++;}
    int query(int l, int r){
        int ret = 0;
        for (l+=sz, r+=sz;l<r;l>>=1, r>>=1){
            if (l&1) ret += tree[l++];
            if (r&1) ret += tree[--r];
        }
        return ret;
    }
}tree;

inline int myabs(int x){
    if (x<0) return -x;
    return x;
}

long long solve(std::vector<int> &s) {
    int n = s.size()/2;
    for (int i=n*2-1;i>=0;i--) if (s[i]<0) pos[-s[i]].push_back(i);
    ll ret = 0;
    vector<int> vec(s.size(), -1);
    int cnt = 1;
    for (int i=0;i<n*2;i++) if (s[i]>0){
        vec[i] = cnt*2;
        vec[pos[s[i]].back()] = cnt*2-1;
        pos[s[i]].pop_back();
        cnt++;
    }
    //for (int i=0;i<n*2;i++) printf("%d ", vec[i]);
    //printf("\n");
    tree.init(n*2+1);
    for (int i=0;i<n*2;i++){
        ret += tree.query(vec[i]+1, n*2+1);
        tree.update(vec[i]);
        s[i] = -s[i];
    }
    reverse(s.begin(), s.end());
    return ret;
}

long long count_swaps(std::vector<int> s) {
  	return min(solve(s), solve(s));
}

• Subtask 1: 10 / 10
• Subtask 2: 0 / 20
• Subtask 3: 20 / 20
• Subtask 4: 15 / 15
• Subtask 5: 0 / 20
• Subtask 6: 0 / 15