实验3

回答

1.加密，每个字母往后移一位
2.转小写，转大写
3.迭代容器起点，终点，新起点，迭代容器所要历遍的函数

代码

#include <iostream>
#include <string>
#include <algorithm>
#include <cctype>


unsigned char func(unsigned char c);
void test1();
void test2();

int main(){
	std::cout<<"测试1：字符串大小写转换\n";
	test1();
	std::cout<<"测试2：字符转变\n";
	test2();
}
unsigned char func(unsigned char c){
	if(c=='z')
	 return 'a';
	
	if(c=='Z')
	 return 'A';
	 
	if(std::isalpha(c))
	 return static_cast<unsigned char>(c+1);
	 
	return c;

}

void test1(){
	std::string s1{"Hello World 2049!"};
	std::cout<<"s1="<<s1<<'\n';
	
	std::string s2;
	for(auto c:s1) 
	  s2 +=std::tolower(c);
	std::cout<<"s2:"<<s2<<'\n';
	
	std::string s3;
	for(auto c:s1)
	 s3 +=std::toupper(c);
	std::cout<<"s3:"<<s3<<'\n';
	 
}

void test2(){
	std::string s1{"I love cosmos!"};
	std::cout<<"s1="<<s1<<'\n';
	
	std::string s2(s1.size(),' ');
	std::transform(s1.begin(),s1.end(),s2.begin(),func);
	std::cout<<"s2:"<<s2<<'\n';
	
}

截图