LeetCode解题报告--Longest Common Prefix

题目：最长公共前缀

Write a function to find the longest common prefix string amongst an array of strings.

分析：题意找出所有字符串的最长公共前缀。 思路简单：如下步骤

1. 找出字符串数组中字符串长度最小的字符串minStr

2. minStr与其余的字符串逐个字符比较，确定最长公共前缀

java 代码：（accepted）

public class LongestCommonPrefix {

/**
* @param args
*/
public static void main(String[] args) {
// TODO Auto-generated method stub
String[] strs = new String[]{"aabd","aabcd","aaccs","aa"};
System.out.println("Longest Common Prefix: " + longestCommonPrefix(strs));
String[] strs1 = new String[]{"a","b"};
System.out.println("Longest Common Prefix 1: " + longestCommonPrefix(strs1));
String[] strs2 = new String[]{"",""};
System.out.println("Longest Common Prefix 2: " + longestCommonPrefix(strs2));
String[] strs3 = new String[]{"ssa","ssab"};
System.out.println("Longest Common Prefix 3: " + longestCommonPrefix(strs3));
String[] strs4 = new String[]{"","b"};
System.out.println("Longest Common Prefix 4: " + longestCommonPrefix(strs4));
String[] strs5 = new String[]{"leet","left","leave","leat"};
System.out.println("Longest Common Prefix 5: " + longestCommonPrefix(strs5));
}

public static String longestCommonPrefix(String[] strs) {
String minStr = "";
int minLength = Integer.MAX_VALUE;

if(strs.length == 1)
return strs[0];
else if(strs.length == 0)
return "";
//Find the smallest length
for(int i = 0;i < strs.length;i ++){
if(strs[i].length() < minLength){
minStr = strs[i];
minLength = strs[i].length();
}
}

for(int i = 0;i < strs.length;i ++){
int j;
for(j = 0;j < minLength;j ++){
if(minStr.charAt(j) != strs[i].charAt(j)){
break;
}
}
if(j < minLength)
minLength = j;
}
return minStr.substring(0,minLength);
}
}

测试结果：

Longest Common Prefix: aa
Longest Common Prefix 1:
Longest Common Prefix 2:
Longest Common Prefix 3: ssa
Longest Common Prefix 4:
Longest Common Prefix 5: le

相关代码放在个人github:https://github.com/gannyee/LeetCode/tree/master/src