百练 4029 数字反转

题目链接：http://bailian.openjudge.cn/practice/4029

# include <stdio.h>int main(){int f;long int str,i,a,a_back;while(scanf("%ld",&str)!=EOF){f=1;if(str<0){printf("-");str=-str;}if(str==0)printf("0");a_back=str%10;for(i=0;str>0;i++){a=str%10;str/=10;if(a==0&&a_back==0)f=0;elsef=1;if(f==1){printf("%d",a);if(a!=0)a_back=a;}}printf("\n");}return 0;}