学步园

将字符串中的字符“*”移动到串的前面，前面的肺“*”字符后移，但不能改变非“*”字符的先后顺序，函数返回串中字符“*”的数量：

public class Move {<br /> public static void main(String []args) throws IOException{<br /> Scanner sc = new Scanner(System.in);<br /> String str = sc.next();<br /> int count = 0;<br /> char []cary = str.toCharArray();<br /> for(int i = 0;i<cary.length;i++){<br /> if(cary[i]=='*'){<br /> count++;<br /> for(int j = i;j > 0;j--){<br /> cary[j]=cary[j-1];<br /> }<br /> cary[0] = '*';<br /> }<br /> }<br /> for(char c :cary){<br /> System.out.print(c);<br /> }<br /> System.out.println();<br /> System.out.println(count);<br /> }<br /> }</p> <p> //结果是：<br /> //555***4444/*/***111<br /> //*******5554444//111<br /> //7<br />

注：在另外一个博客中好心人提的建议：

package charmove;<br /> import java.io.IOException;<br /> public class Move {<br /> public static void main(String[] args) throws IOException {<br /> String str = "555***4444/*/***111";<br /> int num = 10000000;<br /> long t1 = System.currentTimeMillis();<br /> for (int i = 0; i < num; i++) {<br /> move1(str);<br /> }<br /> System.out.println(move1(str));<br /> long t2 = System.currentTimeMillis();<br /> System.out.println("1:" + (t2 - t1));<br /> t1 = System.currentTimeMillis();<br /> for (int i = 0; i < num; i++) {<br /> move2(str);<br /> }<br /> System.out.println(move2(str));<br /> t2 = System.currentTimeMillis();<br /> System.out.println("2:" + (t2 - t1));<br /> }<br /> public static String move1(String str) {<br /> char[] cary = str.toCharArray();<br /> for (int i = 0; i < cary.length; i++) {<br /> if (cary[i] == '*') {<br /> for (int j = i; j > 0; j--) {<br /> cary[j] = cary[j - 1];<br /> }<br /> cary[0] = '*';<br /> }<br /> }<br /> return new String(cary);<br /> }<br /> public static String move2(String str) {<br /> char[] cary = str.toCharArray();<br /> int pos = str.length() - 1;<br /> int pre = pos - 1;<br /> while (pre > -1) {<br /> if (cary[pos] != '*') {<br /> pos--;<br /> if (pos < pre) {<br /> pre = pos;<br /> }<br /> continue;<br /> }<br /> if (cary[pre] == '*') {<br /> pre--;<br /> continue;<br /> }<br /> char ch = cary[pos];<br /> cary[pos] = cary[pre];<br /> cary[pre] = ch;<br /> pre--;<br /> pos--;<br /> }<br /> return new String(cary);<br /> }<br /> } 

速度比我的快一倍，学习了呵..

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