/* space_eater.c */
#include <stdio.h>

int main() {
    char string[] = "wou t      e r";
    char *dest, *cur;
    dest = string;
    cur  = NULL;

    while( *dest != '\0' ) {
        while( *dest != 0x20 ) {
            dest++;
        }

        if ( *dest == 0x20 ) {
            cur = dest;
            while( *cur == 0x20 ) {
                cur++;
            }

            while( *cur != 0x20 && *cur != '\0' ) {
                *dest = *cur;
                *cur  = ' ';
                cur++;
                dest++;
                if ( *cur == '\0' ) {
                    goto END;
                }

            }
        }
    }

END: ;
    printf("%s\n", string);
    return 0;
}