#include <bits/stdc++.h>
using namespace std;
#define pii pair <int, int>
#define fi first
#define se second
#define mp make_pair
#define getbit(x, i) ((x&(1<<i)) != 0)
const int NM = 1000;
int N, S, a[NM+5], a0[NM+5], id[NM+5];
vector <pii> ans;
void op(int i, int j){
ans.push_back(mp(i, j));
a[i] ^= a[j];
}
bool cmp(int x, int y){
return a[x] < a[y];
}
void solve1(){
for (int i = 1; i <= N; i++)
a0[i] = a[i];
for (int i = 1; i < N; i++)
op(i, i+1);
for (int i = N; i >= 1; i--){
int k = 1;
for (int j = 2; j <= i; j++)
if (a0[j] > a0[k]) k = j;
for (int j = k+1; j <= i; j++)
op(j, j-1);
for (int j = k-1; j < i; j++)
if (j > 0) op(j, j+1);
for (int j = k; j < i; j++)
swap(a0[j], a0[j+1]);
}
}
void solve2(){
int tar = N+1;
for (int i = 19; i >= 0; i--){
bool ok = 0;
for (int j = 1; j <= N; j++)
if (getbit(a[j], i)){
ok = 1;
break;
}
if (ok == 0) continue;
tar--;
for (int j = 1; j < tar; j++)
if (getbit(a[j], i) && !getbit(a[j+1], i)){
op(j+1, j);
op(j, j+1);
}
else if (getbit(a[j], i) && getbit(a[j+1], i)){
op(j, j+1);
}
}
}
int main(){
ios_base::sync_with_stdio(0);
cin.tie(0);
cout.tie(0);
cin >> N >> S;
for (int i = 1; i <= N; i++) cin >> a[i];
if (S == 1) solve1();
else solve2();
cout << ans.size() << '\n';
for (int i = 0; i < ans.size(); i++)
cout << ans[i].fi << ' ' << ans[i].se << '\n';
return 0;
}
Compilation message
xorsort.cpp: In function 'int main()':
xorsort.cpp:73:20: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
73 | for (int i = 0; i < ans.size(); i++)
| ~~^~~~~~~~~~~~
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
0 ms |
212 KB |
Output is correct |
2 |
Correct |
1 ms |
212 KB |
Output is correct |
3 |
Correct |
1 ms |
328 KB |
Output is correct |
4 |
Correct |
2 ms |
596 KB |
Output is correct |
5 |
Correct |
2 ms |
584 KB |
Output is correct |
6 |
Correct |
2 ms |
596 KB |
Output is correct |
7 |
Correct |
2 ms |
596 KB |
Output is correct |
8 |
Correct |
2 ms |
596 KB |
Output is correct |
9 |
Correct |
2 ms |
576 KB |
Output is correct |
10 |
Correct |
2 ms |
596 KB |
Output is correct |
11 |
Correct |
1 ms |
340 KB |
Output is correct |
12 |
Correct |
3 ms |
728 KB |
Output is correct |
13 |
Correct |
3 ms |
728 KB |
Output is correct |
14 |
Correct |
3 ms |
728 KB |
Output is correct |
15 |
Correct |
3 ms |
708 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
0 ms |
212 KB |
Output is correct |
2 |
Correct |
1 ms |
212 KB |
Output is correct |
3 |
Correct |
1 ms |
328 KB |
Output is correct |
4 |
Correct |
2 ms |
596 KB |
Output is correct |
5 |
Correct |
2 ms |
584 KB |
Output is correct |
6 |
Correct |
2 ms |
596 KB |
Output is correct |
7 |
Correct |
2 ms |
596 KB |
Output is correct |
8 |
Correct |
2 ms |
596 KB |
Output is correct |
9 |
Correct |
2 ms |
576 KB |
Output is correct |
10 |
Correct |
2 ms |
596 KB |
Output is correct |
11 |
Correct |
1 ms |
340 KB |
Output is correct |
12 |
Correct |
3 ms |
728 KB |
Output is correct |
13 |
Correct |
3 ms |
728 KB |
Output is correct |
14 |
Correct |
3 ms |
728 KB |
Output is correct |
15 |
Correct |
3 ms |
708 KB |
Output is correct |
16 |
Correct |
1 ms |
212 KB |
Output is correct |
17 |
Correct |
2 ms |
596 KB |
Output is correct |
18 |
Correct |
4 ms |
728 KB |
Output is correct |
19 |
Correct |
3 ms |
716 KB |
Output is correct |
20 |
Correct |
3 ms |
728 KB |
Output is correct |
21 |
Correct |
3 ms |
728 KB |
Output is correct |
22 |
Correct |
3 ms |
728 KB |
Output is correct |
23 |
Correct |
3 ms |
708 KB |
Output is correct |
24 |
Correct |
3 ms |
752 KB |
Output is correct |
25 |
Correct |
3 ms |
728 KB |
Output is correct |
26 |
Correct |
7 ms |
984 KB |
Output is correct |
27 |
Correct |
5 ms |
984 KB |
Output is correct |
28 |
Correct |
5 ms |
984 KB |
Output is correct |
29 |
Correct |
5 ms |
984 KB |
Output is correct |
30 |
Correct |
5 ms |
984 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
1 ms |
212 KB |
Output is correct |
2 |
Correct |
1 ms |
212 KB |
Output is correct |
3 |
Correct |
1 ms |
340 KB |
Output is correct |
4 |
Correct |
1 ms |
468 KB |
Output is correct |
5 |
Correct |
5 ms |
936 KB |
Output is correct |
6 |
Correct |
4 ms |
856 KB |
Output is correct |
7 |
Correct |
4 ms |
856 KB |
Output is correct |
8 |
Correct |
4 ms |
856 KB |
Output is correct |
9 |
Correct |
4 ms |
856 KB |
Output is correct |
10 |
Correct |
4 ms |
900 KB |
Output is correct |
11 |
Correct |
4 ms |
856 KB |
Output is correct |
12 |
Correct |
4 ms |
856 KB |
Output is correct |
13 |
Correct |
4 ms |
856 KB |
Output is correct |
14 |
Correct |
4 ms |
856 KB |
Output is correct |
15 |
Correct |
5 ms |
984 KB |
Output is correct |