/in/foo.cc: In function 'int K_th(int, int, int)':
/in/foo.cc:43:12: warning: unused variable 'j' [-Wunused-variable]
     int i, j;
            ^
/in/foo.cc: In function 'int main()':
/in/foo.cc:76:24: warning: format '%s' expects argument of type 'char*', but argument 2 has type 'char (*)[1]' [-Wformat=]
         scanf("%s", &ch);
                        ^
/in/foo.cc:68:12: warning: unused variable 'j' [-Wunused-variable]
     int i, j, x, y;
            ^