/in/foo.c: In function 'main':
/in/foo.c:7:2: warning: implicit declaration of function 'scanf' [-Wimplicit-function-declaration]
  scanf("%d%d",&M,&N);
  ^~~~~
/in/foo.c:7:2: warning: incompatible implicit declaration of built-in function 'scanf'
/in/foo.c:7:2: note: include '<stdio.h>' or provide a declaration of 'scanf'
/in/foo.c:25:2: warning: implicit declaration of function 'printf' [-Wimplicit-function-declaration]
  printf("%d",flag);
  ^~~~~~
/in/foo.c:25:2: warning: incompatible implicit declaration of built-in function 'printf'
/in/foo.c:25:2: note: include '<stdio.h>' or provide a declaration of 'printf'
/in/foo.c: In function 'findmin':
/in/foo.c:32:7: error: 'k' undeclared (first use in this function)
  for( k=0;k<M;k++)
       ^
/in/foo.c:32:7: note: each undeclared identifier is reported only once for each function it appears in
/in/foo.c:32:2: warning: this 'for' clause does not guard... [-Wmisleading-indentation]
  for( k=0;k<M;k++)
  ^~~
/in/foo.c:39:3: note: ...this statement, but the latter is misleadingly indented as if it is guarded by the 'for'
   return n;
   ^~~~~~
/in/foo.c:31:10: warning: unused variable 'K' [-Wunused-variable]
  int n=0,K;
          ^
/in/foo.c: In function 'findmax':
/in/foo.c:44:7: error: 'k' undeclared (first use in this function)
  for( k=0;k<N;k++)
       ^
/in/foo.c:44:2: warning: this 'for' clause does not guard... [-Wmisleading-indentation]
  for( k=0;k<N;k++)
  ^~~
/in/foo.c:51:3: note: ...this statement, but the latter is misleadingly indented as if it is guarded by the 'for'
   return n;
   ^~~~~~
/in/foo.c:43:10: warning: unused variable 'K' [-Wunused-variable]
  int n=0,K;
          ^