Submission #315128

#	Time	Username	Problem	Language	Result	Execution time	Memory
315128		daniel920712	Cat (info1cup19_cat)	C++14	25 / 100	723 ms	262148 KiB

cat

#include <iostream>
#include <stdio.h>
#include <stdlib.h>
#include <vector>

using namespace std;
int all[3000005];
int where[3000005];
vector < pair < int , int > > ans;
int main()
{
    int T,x,y,ok=1,N,i,j;
    scanf("%d",&T);
    while(T--)
    {
        ok=1;
        ans.clear();
        scanf("%d",&N);
        for(i=1;i<=N;i++)
        {
            scanf("%d",&all[i]);
            where[all[i]]=i;
        }
        for(i=1;i<=N/2;i++)
        {
            if(all[i]!=i)
            {
                x=i;
                y=where[i];
                //printf("%d %d\n",x,y);
                if(N-x+1==y)
                {

                    swap(all[x],all[x+1]);
                    where[all[x]]=x;
                    where[all[x+1]]=x+1;
                    ans.push_back(make_pair(x,x+1));
                    swap(all[N-x+1],all[N-x]);
                    where[all[N-x+1]]=N-x+1;
                    where[all[N-x]]=N-x;
                    i--;
                }
                else
                {
                    swap(all[x],all[y]);
                    where[all[x]]=x;
                    where[all[y]]=y;
                    ans.push_back(make_pair(x,y));
                    swap(all[N-x+1],all[N-y+1]);
                    where[all[N-x+1]]=N-x+1;
                    where[all[N-y+1]]=N-y+1;

                    if(all[N-i+1]!=N-i+1) break;
                }

                //printf("%d %d\n",x,y);

            }
            /*for(j=1;j<=N;j++) printf("%d %d\n",all[j],where[all[j]]);
            printf("\n");*/

        }
        for(i=1;i<=N;i++) if(all[i]!=i) ok=0;
        if(ok)
        {
            printf("%d %d\n",ans.size(),ans.size());
            for(auto i:ans) printf("%d %d\n",i.first,i.second);

        }
        else printf("-1\n");
    }
    return 0;
}

Compilation message (stderr)

cat.cpp: In function 'int main()':
cat.cpp:66:22: warning: format '%d' expects argument of type 'int', but argument 2 has type 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} [-Wformat=]
   66 |             printf("%d %d\n",ans.size(),ans.size());
      |                     ~^       ~~~~~~~~~~
      |                      |               |
      |                      int             std::vector<std::pair<int, int> >::size_type {aka long unsigned int}
      |                     %ld
cat.cpp:66:25: warning: format '%d' expects argument of type 'int', but argument 3 has type 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} [-Wformat=]
   66 |             printf("%d %d\n",ans.size(),ans.size());
      |                        ~^               ~~~~~~~~~~
      |                         |                       |
      |                         int                     std::vector<std::pair<int, int> >::size_type {aka long unsigned int}
      |                        %ld
cat.cpp:12:24: warning: unused variable 'j' [-Wunused-variable]
   12 |     int T,x,y,ok=1,N,i,j;
      |                        ^
cat.cpp:13:10: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   13 |     scanf("%d",&T);
      |     ~~~~~^~~~~~~~~
cat.cpp:18:14: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   18 |         scanf("%d",&N);
      |         ~~~~~^~~~~~~~~
cat.cpp:21:18: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   21 |             scanf("%d",&all[i]);
      |             ~~~~~^~~~~~~~~~~~~~

• Subtask 1: 0 / 15
• Subtask 2: 10 / 10
• Subtask 3: 0 / 25
• Subtask 4: 15 / 15
• Subtask 5: 0 / 35