#include <stdio.h>
#include <stdlib.h>

int main(int argc, char** argv) {

  // switch statement
  //
  fprintf(stdout, "using switch:\n");

  char grade = argv[1][0];

  int val = 5;
  
  switch(val) {
  case 3:
    fprintf(stdout, "true...\n");
    break;
  case 4:
    fprintf(stdout, "false...\n");
    break;
  default:
    fprintf(stdout, "neither...\n");
  }


  switch(grade) {
  case 'A':
    fprintf(stdout, "%c: Excellent!\n", grade);
    break;
  case 'B':
  case 'C':
    fprintf(stdout, "%c: Well done\n", grade);
    break;
  case 'D':
    fprintf(stdout, "%c: You passed\n", grade);
    break;
  case 'F':
    fprintf(stdout, "%c: Better try again\n", grade);
    break;
  default:
    fprintf(stdout, "%c: Invalid grade\n", grade);
  }

  /*
  fprintf(stdout, "using if/else if:\n");
  if (grade == 'A') {
    fprintf(stdout, "%c: Excellent!\n", grade);
  }
  else if ((grade == 'B') || (grade == 'C')) {
    fprintf(stdout, "%c: Well done\n", grade);
  }
  else if (grade == 'D') {
    fprintf(stdout, "%c: You passed\n", grade);
  }
  else if (grade == 'F') {
    fprintf(stdout, "%c: Better try again\n", grade);
  }
  else {
    fprintf(stdout, "%c: Invalid grade\n", grade);
  }
  */
  
  // exit gracefully
  //
  return 0;
}