foo.cc: In function ‘int main()’:
foo.cc:4:21: warning: unused variable ‘min’ [-Wunused-variable]
    4 |         int i,j,max,min;
      |                     ^~~
foo.cc:16:34: warning: iteration 3 invokes undefined behavior [-Waggressive-loop-optimizations]
   16 |                         if(a[i][j]>max)
      |                            ~~~~~~^
foo.cc:12:18: note: within this loop
   12 |         for(i=0;i<4;i++)
      |                 ~^~