c - Code crashing in codeblocks -

so i'm newbie programming c, have relatively easy equation i'm messing , can't seem fit why keeps crashing.

is syntax or have random equation crashing it?

#include <stdio.h> #define newyork 1077 #define paris 4487 #define london 4336 #define rome 5113 #define frankfurt 4732 #define sanfrancisco 2888 #define tokyo 7252 #define havana 380 // google maps search  #define b747 614 #define b777 590 #define a330 567 #define a380 634 #define c 1354 // google maps search int main (void)  {  int distance, flight_hours, velocity, speed;   char city; printf ("please enter city fly \n"); printf ("enter first character of name of city in lower case letter \n"); scanf ("%c", city);   switch (city) { case 'n': {     distance = newyork;     break; } case 'p': {     distance = paris;     break; } case 'l': {     distance = london;     break; } case 'r': {     distance = rome;     break; } case 'f': {     distance = frankfurt;     break; } case 's': {     distance = sanfrancisco;     break; } case 't': {     distance = tokyo;     break; } case 'h': {     distance = havana;     break; } default :     printf("you've made error.. \n");     return 0;  }      printf("enter following values type of aircraft flown: \n\n"); printf("enter 1 if boeing 747 \n"); printf("enter 2 if boeing 777 \n"); printf("enter 3 if airbus 330 \n"); printf("enter 4 if airbus 380 \n"); printf("enter 5 if concorde \n");  scanf("%f", &velocity);   if (velocity == 1)     speed = b747; else if (velocity == 2)     speed = b777; else if (velocity == 3)     speed = a330; else if (velocity == 4)     speed = a380; else if (velocity == 5)     speed = c; else {     printf ("your entry invalid \n");     return 0;  }  flight_hours = distance/speed; ((float) (distance%speed)/(float)speed)*60; return 0; } 

change scanf ("%c", city); scanf ("%c", &city);

also, make program work every time, do:

scanf (" %c", &city); 

also, check errors, checking return values of scanf(). if returns eof, there error.

also, check this question return values of scanf().