input:
2 2
10
Output:
2.00
1 1
Algo:
cin>>a>>b; cin>>k;
    for(i=0; i<=k-1; i++){
              for(j=0;j<=k-i; j++){
               l=i*i+j*j;
               g=i*a+j*b;
               x=g-l;
              if(x>=r){n++; r=x; s[n]=r; si[n]=i; sj[n]=j;}}}
      for(int y=1; y<=n; y++){ if(s[n]==s[y]){
              cout<<fixed<<setprecision(2)<<s[y];
              cout<<endl<<si[y]<<" "<<sj[y]<<endl; } }

Is it right?