Submission #745639

#	Time	Username	Problem	Language	Result	Execution time	Memory
745639		Dan4Life	Sorting (IOI15_sorting)	C++17	20 / 100	2 ms	468 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];

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

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