好學驛站

加密解密時可以用到，只支持小寫字母的轉換。

?private String dmix(String str1)
??? {
??????? int MAX_COUNT = 20;
??????? char ca[] = str1.toCharArray();
??????? int count = 0;
??????? for(int i = 0; i < ca.length; i++)
??????? {
??????????? int a = ca[i] - count;
??????????? ca[i] = (char)a;
??????????? if(ca[i] < 'a')
??????????????? ca[i] += '\032';
??????????? count = ++count % MAX_COUNT;
??????? }

??????? StringBuffer sb = new StringBuffer();
??????? sb.append(ca);
??????? return sb.toString();
??? }
??? public String mix(String str1)
??? {
??? ?int MAX_COUNT = 20;
??????? char ca[] = str1.toCharArray();
??????? int count = 0;
??????? for(int i = 0; i < ca.length; i++)
??????? {
??????? ?int a=0;
??????????? a = ca[i] + count;
??????????? ca[i] = (char)a;
??????????? if(ca[i] > 'z')
??????????????? ca[i] -= '\032';
??????????? count = ++count % MAX_COUNT;
??????? }

??????? StringBuffer sb = new StringBuffer();
??????? sb.append(ca);
??????? return sb.toString();
??? }