to do, good!!!

//https://otvet.mail.ru/question/217817109
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#include <stdio.h>
#define M 4

int main()
{
    int i,j,k,fk,oi,oj,ni,nj,arr[M][M]={1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16};


    for(i=0;i<M;i++)
    {
       for(j=i;j<M;j++)
          arr[i][j]*=-1;
    }

    fk= (M*M-M)/2;
    //oi=1;oj=0;
    for(i=1;i<M;i++)
    {
       for(j=0;j<i;j++)
          {
              for(k=0;k<fk;k++)
              {
                  printf("k-%d\t",k);
              }
              printf("\n");
          }
          //arr[i][j]=99;
    }

    for(i=0;i<M;i++)
    {
       for(j=0;j<M;j++)
          printf("%d\t",arr[i][j]);
    printf("\n");
    }
    return 0;
}