Submission #745654

#	Time	Username	Problem	Language	Result	Execution time	Memory
745654		Dan4Life	Sorting (IOI15_sorting)	C++17	0 / 100	7 ms	980 KiB

sorting

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

void swp(int i, int j){ 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], vis[i]=0, pos[a[i]] = i;
    for(int i = 0; i < m; i++)
        swp(x[i],y[i]), P[i]=Q[i]=0;
    int tot = 0;
    for(int i = 0; i < n; i++){
        if(vis[i]) continue;
        vector<int> v; v.clear(); int j = i;
        while(!vis[j]) vis[j]=1, v.push_back(j), j = a[j];
        int s = (int)v.size();
        for(int j = 0; j < s-1; j++)
            P[tot] = pos[a[v[j]]], Q[tot++] = pos[a[v[j+1]]],swp(v[j],v[j+1]);
    }
    return (is_sorted(a,a+n) and tot<=m)?m:mxN;
}

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

Compilation message (stderr)

sorting.cpp: In function 'int chk(int, int*, int*)':
sorting.cpp:20:17: warning: declaration of 'j' shadows a previous local [-Wshadow]
   20 |         for(int j = 0; j < s-1; j++)
      |                 ^
sorting.cpp:17:39: note: shadowed declaration is here
   17 |         vector<int> v; v.clear(); int j = i;
      |                                       ^

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