/in/foo.cc: In function 'int main()':
/in/foo.cc:14:1: warning: this 'for' clause does not guard... [-Wmisleading-indentation]
 for (j=1;j<=m;j++)    
 ^~~
/in/foo.cc:15:14: note: ...this statement, but the latter is misleadingly indented as if it is guarded by the 'for'
 cin>>a[i][j];find_max();//第一次特判
              ^~~~~~~~