Submission #143826

#	Time	Username	Problem	Language	Result	Execution time	Memory
143826		shdut	Arranging Shoes (IOI19_shoes)	C++14	Compilation error	0 ms	0 KiB

shoes

#include "shoes.h"
#include <vector>
#include <map>

#define N 100005
#define pb push_back
#define x first
#define y second
#define ls p<<1
#define rs p<<1|1
#define vi std::vector<int>
#define rep(i, a, b) for(int i = a; i < b; i++)

int t[N << 2];
void build(int p, int l, int r){
    if(l == r){
        t[p] = 1;
        return;
    }
    int m = (l + r) >> 1;
    build(ls, l, m);
    build(rs, m+1, r);
    t[p] = t[ls] + t[rs];
}
void upd(int p, int l, int r, int x, int v){
    t[p] += v;
    if(l == r){
        return;
    }
    int m = (l+r) >> 1;
    if(x <= m)upd(ls, l, m, x, v);
    else upd(rs, m+1, r, x, v);
}
int query(int p, int l, int r, int x, int y){
    if(x > y)return 0;
    if(l >= x && r <= y)return t[p];
    int m = (l+r) >> 1, ans = 0;
    if(x <= m)ans = query(ls, l, m, x, y);
    if(y > m)ans += query(rs, m+1, r, x, y);
    return ans;
}
std::map<int, int>b[N];
long long count_swaps(std::vector<int> s) {
    int n = s.size();        
    build(1, 0, n-1);
    rep(i, 1, n+1)b[i].clear();
    vi a;
    rep(i, 0, n){
        if(s[i] < 0)a.pb(i);
        else b[s[i]][i] = 1;
    }
    std:reverse(a.begin(), a.end());
    long long ans = 0;
    for(auto &x : a){
        int i = -s[x], v;
        auto it = b[i].lower_bound(x);
        if(it != b[i].end()){
            int nw = 0;
            while(it != b[i].end()){
                int k =  it->x, w = it->y;
                v = query(1, 0, n-1, x+1, k-1);
                ans += 1LL * v * w;
                upd(1, 0, n-1, k, -w);
                nw += w;
                auto ne = it;
                it++;
                b[i].erase(ne);
            }
            if(nw){
                b[i][x] = nw - 1;
            }
            upd(1, 0, n-1, x, nw);
        }
        else{
            it--;
            v = query(1, 0, n-1, it->x+1, x-1);
            ans += v + 1;
            upd(1, 0, n-1, it->x, -1);
            upd(1, 0, n-1, x, 1);
            b[i].erase(it);
        }
    }
    return ans;
}

Compilation message (stderr)

shoes.cpp: In function 'long long int count_swaps(std::vector<int>)':
shoes.cpp:52:9: error: 'reverse' was not declared in this scope
     std:reverse(a.begin(), a.end());
         ^~~~~~~
shoes.cpp:52:5: warning: label 'std' defined but not used [-Wunused-label]
     std:reverse(a.begin(), a.end());
     ^~~