Submission #1040977

#	Time	Username	Problem	Language	Result	Execution time	Memory
1040977		idas	Arranging Shoes (IOI19_shoes)	C++17	50 / 100	1100 ms	6704 KiB

shoes

#include <bits/stdc++.h>
#define FOR(i, begin, end) for(int i=(begin); i<(end); i++)
#define pb push_back

using namespace std;
typedef long long ll;
typedef vector<int> vi;

const int N=2e5+10;
int n, cn[N], pos[N];
vi p_pos, n_pos[N];

long long count_swaps(vector<int> s) {
    n=s.size();

    ll ans=0;
    for(int i=n-1; i>=0; i-=2){
        if(s[i]>0){
            int in;
            for(int j=i-1; j>=0; j--){
                if(s[j]==-s[i]){
                    in=j;
                    break;
                }
            }

            FOR(j, in+1, i)
            {
                swap(s[j-1], s[j]);
                ans++;
            }
        }
        else{
            int in;
            for(int j=i-1; j>=0; j--){
                if(s[j]==-s[i]){
                    in=j;
                    break;
                }
            }

            FOR(j, in+1, i+1)
            {
                swap(s[j-1], s[j]);
                ans++;
            }
        }
    }

    return ans;
}

Compilation message (stderr)

shoes.cpp: In function 'long long int count_swaps(std::vector<int>)':
shoes.cpp:42:17: warning: 'in' may be used uninitialized in this function [-Wmaybe-uninitialized]
   42 |             FOR(j, in+1, i+1)
      |                 ^
shoes.cpp:27:17: warning: 'in' may be used uninitialized in this function [-Wmaybe-uninitialized]
   27 |             FOR(j, in+1, i)
      |                 ^

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