Submission #16657

#	Time	Username	Problem	Language	Result	Execution time	Memory
16657		suhgyuho_william	Sorting (IOI15_sorting)	C++98	0 / 100	3 ms	384 KiB

sorting

#include "sorting.h"
#include <algorithm>
using namespace std;

int a[200002],location[200002];
int where[200002],last[200002];

int findSwapPairs(int N, int S[], int M, int X[], int Y[], int P[], int Q[]) {
    int i,n=N,R;
    int left,right;
    int cnt;

    left=0;
    right=M;
    while(1){
        R=(left+right)/2;
        if(left==right) break;

        for(i=0;i<n;i++){
            a[i]=S[i];
            location[a[i]]=i;
            where[a[i]]=i;
        }
        for(i=0;i<R;i++){
            location[a[X[i]]]=Y[i];
            location[a[Y[i]]]=X[i];
            swap(a[X[i]],a[Y[i]]);
        }
        cnt=-1;
        for(i=0;i<n;i++) last[i]=a[i];
        for(i=0;i<n;i++) a[i]=S[i];
        for(i=0;i<n;i++){
            if(location[i]==i) continue;
            cnt++;
            if(cnt>=R) break;
            where[a[X[cnt]]]=Y[cnt];
            where[a[Y[cnt]]]=X[cnt];
            swap(a[X[cnt]],a[Y[cnt]]);

            P[cnt]=where[i];
            Q[cnt]=where[last[i]];
            location[last[i]]=location[i];
            location[i]=i;

            where[a[P[cnt]]]=Q[cnt];
            where[a[Q[cnt]]]=P[cnt];
            swap(a[P[cnt]],a[Q[cnt]]);
        }
        if(cnt>=R){
            left=R+1;
        }else{
            right=R;
        }
    }
    for(i=cnt+1;i<R;i++) P[i]=Q[i]=0;

	return R;
}

Compilation message (stderr)

sorting.cpp: In function 'int findSwapPairs(int, int*, int, int*, int*, int*, int*)':
sorting.cpp:11:9: warning: 'cnt' may be used uninitialized in this function [-Wmaybe-uninitialized]
     int cnt;
         ^~~

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