Submission #318154

#	Time	Username	Problem	Language	Result	Execution time	Memory
318154		tigicha	Sorting (IOI15_sorting)	C++14	100 / 100	386 ms	21460 KiB

sorting

#include <bits/stdc++.h>
#include "sorting.h"
using namespace std;
int l, r, ans, m, b[500005], a[500005];
vector<pair<int, int> > v;
int findSwapPairs(int N, int S[], int M, int X[], int Y[], int P[], int Q[]) {
    l=0;
	r=M;
	ans=-1;
    while(l<=r){
        m=(l+r)/2;
        for(int i=0; i<N; i++)
        b[i]=S[i];
        for(int i=0; i<m; i++)
        swap(b[X[i]], b[Y[i]]);
        for(int i=0; i<N; i++)
        a[b[i]]=i;
        v.clear();
        for(int i=0; i<N; i++){
            if(b[i]==i) continue;
            v.push_back(make_pair(i, b[i]));
            swap(b[i], b[a[i]]);
            swap(a[i], a[b[a[i]]]);   
        }
        if(v.size()>m) l=m+1;
        else{
            for(int i=0; i<N; i++){
                b[i]=S[i];
                a[b[i]]=i;
            }
            for(int i=0; i<M; i++){
                swap(a[b[X[i]]], a[b[Y[i]]]);
                swap(b[X[i]], b[Y[i]]);
                if(i<v.size()){
                    P[i]=a[v[i].first];
                    Q[i]=a[v[i].second];
                    swap(a[v[i].first], a[v[i].second]);
                    swap(b[a[v[i].first]], b[a[v[i].second]]);                    
                }
                else{
				P[i]=0;
				Q[i]=0;
				}
            }
            r=m-1;
            ans=m;
        }
    }
    return ans;
}

Compilation message (stderr)

sorting.cpp: In function 'int findSwapPairs(int, int*, int, int*, int*, int*, int*)':
sorting.cpp:25:20: warning: comparison of integer expressions of different signedness: 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} and 'int' [-Wsign-compare]
   25 |         if(v.size()>m) l=m+1;
      |            ~~~~~~~~^~
sorting.cpp:34:21: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   34 |                 if(i<v.size()){
      |                    ~^~~~~~~~~

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