字符串反转-java

/*

*将一个字符串反转：Hello world --> world Hello

*

*/ 

 

//对一个char数组进行整体反转

public static void subReverse(char[] str, Integer begin, Integer end) {

char temp;

while (begin <= end) {

temp = str[begin];

str[begin] = str[end];

str[end] = temp;

begin++;

end--;

}

}

public static void reverse(String str) {

// String str = "Hello World Welcome to china";

//构造每个分割的下标

List index = new ArrayList<Integer>();

char[] str1 = str.toCharArray();

index.add(-1);

for (int k = 0; k < str1.length; k++) {

if (str1[k] == ' ')

index.add(k);

}

index.add(str1.length);

//首先每个单词反转

for (int k = 0; k < index.size() - 1; k++) {

subReverse(str1, (Integer) index.get(k) + 1, (Integer) index

.get(k + 1) - 1);

}

//再对整体进行反转

subReverse(str1, 0, str1.length - 1);

for (int i = 0; i < str1.length; i++) {

System.out.print(str1[i]);

}

}