【思路】:tolower(),toupper()。
【AC代码】:
#include <iostream> #include <algorithm> #include <vector> #include <cstdio> #include <cstring> using namespace std; #define MAX 20+5 int main() { //freopen("in.txt", "r", stdin); char str[MAX]; int i = 0; cin >> str; //trans for (i = 0; i < strlen(str); i++) { if (str[i] >= 'a' && str[i] <= 'z') str[i] = toupper(str[i]); else if (str[i] >= 'A' && str[i] <= 'Z') str[i] = tolower(str[i]); } //output cout << str; }
原文:http://blog.csdn.net/weijj6608/article/details/44630951