Submission #768898

#	Time	Username	Problem	Language	Result	Execution time	Memory
768898		emad234	Arranging Shoes (IOI19_shoes)	C++17	100 / 100	331 ms	33144 KiB

shoes

#include <bits/stdc++.h>
#define aint(v) ((v).bvin(),(v).end())
#define ll long long
#define F first
#define S second
using namespace std;
const int mod = 1e9 + 7;
const int mxN = 8e6 + 1;
bool vis[mxN];
int seg[mxN];
int st,e,N;
int query(int l = 1,int r = N,int ind = 1){
  if(l > e || r < st) return 0;
  if(l >= st && r <= e) return seg[ind];
  int md = (l + r) / 2;
  return query(l,md,ind * 2) + query(md + 1,r,ind * 2 + 1);
}
void update(int ind){
  ind += N;
  seg[ind] = 1;
  ind /= 2;
  while(ind){
    seg[ind] = seg[ind * 2] + seg[ind * 2 + 1];
    ind /= 2;
  }
}
map<int,set<int>>mp;
ll count_swaps(vector<int> s) {
  ll ans = 0;
  N = exp2(ceil(log2(s.size())));
  for(int i = 0;i < s.size();i++){
    mp[s[i]].insert(i);
  }
  for(int i = 0;i < s.size();i++){
    if(vis[i]) continue;
    ans += (s[i] > 0);
    auto x = *(mp[s[i] * -1].begin());
    mp[s[i] * -1].erase(mp[s[i] * -1].begin());
    mp[s[i]].erase(mp[s[i]].begin());
    vis[i] = 1;
    vis[x] = 1;
    st = i + 1;e = x + 1;
    ans -= query();
    // cout<<query()<<' ';
    ans += x - i - 1;
    update(i);
    update(x);
  }
  return ans;
}
// 
// 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;
// }

Compilation message (stderr)

shoes.cpp: In function 'long long int count_swaps(std::vector<int>)':
shoes.cpp:31:19: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   31 |   for(int i = 0;i < s.size();i++){
      |                 ~~^~~~~~~~~~
shoes.cpp:34:19: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   34 |   for(int i = 0;i < s.size();i++){
      |                 ~~^~~~~~~~~~

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