Submission #571890

#	Time	Username	Problem	Language	Result	Execution time	Memory
571890		kwongweng	Sorting (IOI15_sorting)	C++17	36 / 100	2 ms	424 KiB

sorting

#include "sorting.h"
#include <bits/stdc++.h>
using namespace std;

typedef vector<int> vi;
typedef long long ll;
typedef long double ld;

#define FOR(i,a,b) for(int i = a; i < b; i++)
#define ROF(i,a,b) for(int i = a; i >= b; i--)
#define fi first
#define se second
#define pb push_back

int findSwapPairs(int N, int S[], int M, int X[], int Y[], int P[], int Q[]) {
	int pos[N];
	FOR(i,0,N){
		pos[S[i]] = i;
	}
	vi s(N); FOR(i,0,N) s[i] = S[i];
	if (X[0]==Y[0]){
		int cnt = 0;
		FOR(i,0,N-1){
			if (pos[i] == i) continue;
			P[cnt] = pos[i];
			Q[cnt] = i;
			cnt++;
			s[pos[i]] = s[i];
			pos[s[i]] = pos[i];
		}
		return cnt;
	}
	FOR(i,0,N-1){
		if (X[i] != Y[i]){
			swap(pos[S[X[i]]], pos[S[Y[i]]]);
			swap(S[X[i]], S[Y[i]]);
		}
		if (i == N-2){
			if (S[0] == 0){
				P[i] = 0; Q[i] = 0;
			}else{
				P[i] = 0, Q[i] = 1;
			}
			if (P[i] != Q[i]){
				swap(pos[S[P[i]]], pos[S[Q[i]]]);
				swap(S[P[i]], S[Q[i]]);
			}
			break;
		}	
		P[i] = pos[i+2];
		Q[i] = i+2;
		if (P[i] != Q[i]){
			swap(pos[S[P[i]]], pos[S[Q[i]]]);
			swap(S[P[i]], S[Q[i]]);
		}
	}
	return N-1;
}

Compilation message (stderr)

sorting.cpp: In function 'int findSwapPairs(int, int*, int, int*, int*, int*, int*)':
sorting.cpp:15:39: warning: unused parameter 'M' [-Wunused-parameter]
   15 | int findSwapPairs(int N, int S[], int M, int X[], int Y[], int P[], int Q[]) {
      |                                   ~~~~^

• Subtask 1: 8 / 8
• Subtask 2: 12 / 12
• Subtask 3: 16 / 16
• Subtask 4: 0 / 18
• Subtask 5: 0 / 20
• Subtask 6: 0 / 26