Submission #745630

#	Time	Username	Problem	Language	Result	Execution time	Memory
745630		Dan4Life	Sorting (IOI15_sorting)	C++17	0 / 100	1 ms	468 KiB

sorting

#include "sorting.h"
#include <bits/stdc++.h>
using namespace std;
const int mxN = (int)2e5+10;
int n, m, a[mxN], temp[mxN], x[mxN], y[mxN], pos[mxN];

void swp(int a[], int i, int j){
    if(i==j) return;
    swap(pos[a[i]],pos[a[j]]), swap(a[i],a[j]);
}

int chk(int m, int P[], int Q[]){
    for(int i = 0; i < n; i++) a[i] = temp[i], pos[a[i]] = i;
    for(int i = 0; i < m; i++) swp(a,x[i],y[i]),P[i]=Q[i]=0;
    for(int i = 0; i < n; i++){
        if(pos[i]==i) continue;
        P[i] = i, Q[i] = pos[i];
        swp(a,i,pos[i]);
    }
    for(int i = 0; i < m; i++) swp(a,x[i],y[i]), swp(a,P[i],Q[i]);
    for(int i = 0; i < m; i++){
        if(is_sorted(a,a+n)) return i;
        swp(a,x[i],y[i]);
        if(is_sorted(a,a+n)){ P[i]=Q[i]=0; return i+1; }
        swp(a,P[i],Q[i]);
    }
	return m;
}

int findSwapPairs(int N, int A[], int M, int X[], int Y[], int P[], int Q[]) {
    n = N, m = M;
    for(int i = 0; i < n; i++) a[i] = temp[i] = A[i];
    for(int i = 0; i < m; i++) x[i] = X[i], y[i] = Y[i];
    int l = 0, r = m;
    while(l<r){
        int mid = (l+r)/2;
        if(chk(mid,P,Q)<=mid) r=mid;
        else l=mid+1;
    }
    return chk(l,P,Q);
}

Compilation message (stderr)

sorting.cpp: In function 'void swp(int*, int, int)':
sorting.cpp:7:14: warning: declaration of 'a' shadows a global declaration [-Wshadow]
    7 | void swp(int a[], int i, int j){
      |          ~~~~^~~
sorting.cpp:5:11: note: shadowed declaration is here
    5 | int n, m, a[mxN], temp[mxN], x[mxN], y[mxN], pos[mxN];
      |           ^
sorting.cpp: In function 'int chk(int, int*, int*)':
sorting.cpp:12:13: warning: declaration of 'm' shadows a global declaration [-Wshadow]
   12 | int chk(int m, int P[], int Q[]){
      |         ~~~~^
sorting.cpp:5:8: note: shadowed declaration is here
    5 | int n, m, a[mxN], temp[mxN], x[mxN], y[mxN], pos[mxN];
      |        ^

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