/*
* 字符串左移,如abcdefghi左移4位后为efghiabcd
*/
public class ShiftLeft {
static String reverStr(String s){
int low = 0;
int high = s.length()-1;
char[] temp = new char[s.length()];
while(low <= high){
temp[low] = s.charAt(high);
temp[high] = s.charAt(low);
low++;
high--;
}
return String.valueOf(temp);
}
/**
*
* @param s 要移位的字符串
* @param digits 向左移动的位数
*/
static String shift(String s,int digits){
if(digits==0){
return s;
}else if(digits>0){
digits = digits % s.length();
String left = reverStr(s.substring(0, digits));
String right = reverStr(s.substring(digits));
String result = reverStr(left+right);
return result;
}else{ //此时变为向右移digits位,即向左移动s.length() - digits位
digits = -digits;
digits = digits % s.length();
return shift(s,s.length()-digits);
}
}
public static void main(String[] args) {
String s = "abcdefghi";
System.out.println(shift(s,-3));
}
}
字符串左移位
最新推荐文章于 2021-01-02 13:51:32 发布