Submission #1090103

#	Time	Username	Problem	Language	Result	Execution time	Memory
1090103		idk__	Xor Sort (eJOI20_xorsort)	C++14	40 / 100	49 ms	1088 KiB

xorsort

#include <bits/stdc++.h>
using namespace std;
int a[1001], n, s;
vector<pair<int, int>>op;
void s1(){
    int b[n];
    for(int i = 0;i < n; i++)b[i]=a[i];
    for(int i = 0;i < n-1; i++)op.push_back({i, i+1}), b[i]^=b[i+1];

    for(int i = n-1; i>=0; i--){
        int mxi = 0;
        for(int j = 0;j <= i; j++)if(b[j] > b[mxi])mxi = j;
        for(int j = mxi; j < i; j++)op.push_back({j+1, j}), b[j+1]^=b[j];
        for(int j = mxi-1; j >=1; j--)op.push_back({j, j-1}), b[j]^=b[j-1];
    
        for(int j=mxi; j<i; j++) swap(b[j], b[j+1]);
    
    }
    // cout << endl;
    // for(auto i : b)cout << i << " ";
    // cout << endl;

}

void s2(){
    for(int i = 19; i>=0; i--){

        for(int j = 0;j < n-1; j++){
            
            int bt = (1 << i);

            if(a[j+1] >= (1<<(i+1)))break;
            //1, 0, C=1
            //0, 1
            //1, 1, c = 2
            //0, 0
            if((bt&a[j]) and !(bt&a[j+1]))op.push_back({j+1, j}), a[j+1]^=a[j];
            if((bt&a[j]) and (bt&a[j+1]))op.push_back({j, j+1}), a[j]^=a[j+1];
            

        }
       
    }
}

int main() {
    ios_base::sync_with_stdio(false);
    cin.tie(0);
    cout.tie(0);
    cin >> n >> s;
    for(int i = 0;i < n; i++)cin >> a[i];

    if(s==1)s1();
    else s2();

    cout << op.size() << endl;
   for(auto [i, j] : op)cout << i+1 << " " << j+1 << endl;
    
   //for(int i = 0;i < n; i++)cout << a[i] << " ";

    
    
    }

Compilation message (stderr)

xorsort.cpp: In function 'int main()':
xorsort.cpp:57:13: warning: structured bindings only available with '-std=c++17' or '-std=gnu++17'
   57 |    for(auto [i, j] : op)cout << i+1 << " " << j+1 << endl;
      |             ^

• Subtask 1: 0 / 25
• Subtask 2: 0 / 35
• Subtask 3: 40 / 40