#include "sorting.h"
#include <bits/stdc++.h>
#define MAXN 200015
using namespace std;
int bk[MAXN],pos_bk[MAXN],pre[MAXN],pos_pre[MAXN];
int solve(int N,int n,int S[],int P[],int Q[],int X[],int Y[]){
int now=0,cnt_same=0;
for (int i=0;i<N;i++){
bk[i]=i; pos_bk[i]=i;
pre[i]=S[i]; pos_pre[S[i]]=i;
if (pre[i]==i) cnt_same++;
}
for (int i=n-1;i>=0;i--){
swap(bk[X[i]],bk[Y[i]]);
pos_bk[bk[X[i]]]=X[i];
pos_bk[bk[Y[i]]]=Y[i];
}
for (int i=0;i<n;i++){
if (cnt_same==N) return i;
if (pre[X[i]]==X[i]) cnt_same--;
if (pre[Y[i]]==Y[i]) cnt_same--;
swap(pre[X[i]],pre[Y[i]]);
if (pre[X[i]]==X[i]) cnt_same++;
if (pre[Y[i]]==Y[i]) cnt_same++;
pos_pre[pre[X[i]]]=X[i];
pos_pre[pre[Y[i]]]=Y[i];
swap(bk[X[i]],bk[Y[i]]);
pos_bk[bk[X[i]]]=X[i];
pos_bk[bk[Y[i]]]=Y[i];
now=i;
while (now<N&&pos_pre[now]==pos_bk[now])
now++;
if (now>=N) continue;
P[i]=pos_pre[now]; Q[i]=pos_bk[now];
swap(pre[pos_pre[now]],pre[pos_bk[now]]);
pos_pre[pre[pos_pre[now]]]=pos_pre[now];
pos_pre[pre[pos_bk[now]]]=pos_bk[now];
}
bool flag=1;
for (int i=0;i<N;i++){
if (pre[i]!=i) flag=0;
}
if (flag) return n;
else return 1e9;
}
int findSwapPairs(int N, int S[], int M, int X[], int Y[], int P[], int Q[]) {
int l=0,r=M;
while (l<r){
int mid=(l+r)>>1;
if (solve(N,mid,S,P,Q,X,Y)<1e8) r=mid;
else l=mid+1;
}
return solve(N,l,S,P,Q,X,Y);
/*
for (int i=0;i<M;i++){
int need=solve(N,i,S,P,Q,X,Y);
if (need<1e8){
cout<<i<<" OK\n";
ans=min(ans,i);
}
else cout<<i<<" NO\n";
}
*/
}
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
0 ms |
212 KB |
Output is correct |
2 |
Correct |
0 ms |
212 KB |
Output is correct |
3 |
Correct |
0 ms |
212 KB |
Output is correct |
4 |
Correct |
0 ms |
212 KB |
Output is correct |
5 |
Correct |
1 ms |
212 KB |
Output is correct |
6 |
Correct |
0 ms |
212 KB |
Output is correct |
7 |
Correct |
0 ms |
212 KB |
Output is correct |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
0 ms |
212 KB |
Output is correct |
2 |
Correct |
0 ms |
212 KB |
Output is correct |
3 |
Correct |
0 ms |
212 KB |
Output is correct |
4 |
Correct |
0 ms |
212 KB |
Output is correct |
5 |
Correct |
1 ms |
212 KB |
Output is correct |
6 |
Correct |
0 ms |
212 KB |
Output is correct |
7 |
Correct |
0 ms |
212 KB |
Output is correct |
8 |
Correct |
0 ms |
212 KB |
Output is correct |
9 |
Correct |
1 ms |
212 KB |
Output is correct |
10 |
Correct |
0 ms |
340 KB |
Output is correct |
11 |
Correct |
1 ms |
340 KB |
Output is correct |
12 |
Correct |
0 ms |
340 KB |
Output is correct |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
0 ms |
212 KB |
Output is correct |
2 |
Correct |
0 ms |
212 KB |
Output is correct |
3 |
Correct |
1 ms |
340 KB |
Output is correct |
4 |
Correct |
1 ms |
340 KB |
Output is correct |
5 |
Correct |
1 ms |
340 KB |
Output is correct |
6 |
Incorrect |
0 ms |
212 KB |
Output isn't correct |
7 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
0 ms |
212 KB |
Output is correct |
2 |
Correct |
0 ms |
212 KB |
Output is correct |
3 |
Correct |
0 ms |
212 KB |
Output is correct |
4 |
Correct |
0 ms |
212 KB |
Output is correct |
5 |
Correct |
1 ms |
212 KB |
Output is correct |
6 |
Correct |
0 ms |
212 KB |
Output is correct |
7 |
Correct |
0 ms |
212 KB |
Output is correct |
8 |
Correct |
0 ms |
212 KB |
Output is correct |
9 |
Correct |
1 ms |
212 KB |
Output is correct |
10 |
Correct |
0 ms |
340 KB |
Output is correct |
11 |
Correct |
1 ms |
340 KB |
Output is correct |
12 |
Correct |
0 ms |
340 KB |
Output is correct |
13 |
Correct |
0 ms |
212 KB |
Output is correct |
14 |
Correct |
0 ms |
212 KB |
Output is correct |
15 |
Correct |
1 ms |
340 KB |
Output is correct |
16 |
Correct |
1 ms |
340 KB |
Output is correct |
17 |
Correct |
1 ms |
340 KB |
Output is correct |
18 |
Incorrect |
0 ms |
212 KB |
Output isn't correct |
19 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
2 ms |
340 KB |
Output is correct |
2 |
Correct |
2 ms |
428 KB |
Output is correct |
3 |
Incorrect |
3 ms |
340 KB |
Output isn't correct |
4 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
2 ms |
340 KB |
Output is correct |
2 |
Correct |
2 ms |
428 KB |
Output is correct |
3 |
Incorrect |
3 ms |
340 KB |
Output isn't correct |
4 |
Halted |
0 ms |
0 KB |
- |