poj 2141 Message Decowding

poj 2141 Message Decowding

#include <iostream>#include <map>#include <string>#include <cctype>using namespace std;map<char, char> m;int main(){    string input, key;    int len, i;    cin >> key;    cin.get();    len = key.length();    for (i = 0; i < len; i++)        m['a'+i] = key[i];    getline(cin, input);    len = input.length();    char temp;    for (i = 0; i < len; i++)    {        if (isupper(input[i]))//判断是否为大写字符，如果是将其转换为小写，得到结果后再大写输出         { temp = tolower(input[i]); temp = m[temp]; temp = toupper(temp); cout << temp;        }        else if (isspace(input[i])) //判断是否为空格 cout << input[i];        elsecout << m[input[i]];    }    cout << endl;}