include <stdio.h> include <string.h> int main(){ int num,i,len;char str[20]={0};printf("please input a number:");scanf("%d",&num);sprintf(str,"%d",num);len=strlen(str);for(i=0;i<len;i++){ str[i]=(str[i]-'0'+2)%10+'0';} printf("%s\n",str);retur...