1 #include <stdio.h> 2 3 /* count lines in input */ 4 int 5 main() 6 { 7 int c, pc; /* c = character, pc = previous character */ 8 9 /* set pc to a value that wouldn't match any character, in case 10 this program is ever modified to get rid of multiples of other 11 characters */ 12 13 pc = EOF; 14 15 while ((c = getchar()) != EOF) { 16 if (c == ' ') 17 if (pc != ' ') /* or if (pc != c) */ 18 putchar(c); 19 20 /* We haven't met 'else' yet, so we have to be a little clumsy */ 21 if (c != ' ') 22 putchar(c); 23 pc = c; 24 } 25 26 return 0; 27 }
PS: PC 模拟 C前一个节点!