《C++编程》第3章第28题

#include<stdio.h>#include<string.h>int main(){int i,n;char s[100];while(1){printf("请输入一串字符\n");gets(s);n=strlen(s);for(i=0;i<n;i++){if(s[i]>=65&&s[i]<=90)s[i]=s[i]+32;else if(s[i]>=87&&s[i]<=122)s[i]=s[i]-32;elses[i]=s[i];}printf("大小写转化后\n");for(i=0;i<n;i++)printf("%c",s[i]);}return 0;}