Title 14, the longest common prefix

I, entitled

¹

Second, the idea

Traverse on the right

Third, the code

public class T014 {

	public static void main(String[] args) {
		// TODO Auto-generated method stub
		String strs1[] = {"flower","flow","flight"};
		System.out.println( longestCommonPrefix( strs1 ) );		//"fl"
		String strs2[]  =  { "dog","racecar","car" };
		System.out.println( longestCommonPrefix( strs2 ) );		//""
		String strs3[]  =  { "","b" };
		System.out.println( longestCommonPrefix( strs3 ) );		//""
	}
	
    public static String longestCommonPrefix(String[] strs) {

    	//如果输入的字符串个数为0或者1可以直接输出结果
    	if( strs.length == 0 )
    		return "";
    	else if( strs.length == 1 )
    		return strs[ 0 ];
    	
    	String output = "";							//用来存储输出的结果，也就是最长公共前缀
    	boolean next = true;						//用来判断遍历是否结束
    	int i = 1;									//标记当前所对比的是第几个字符

		//依次判断每一个字符是否相同
    	while( next ) {

    		//依次遍历判断每一个字符串的第i个字符是否相同
        	for( int j = 1; j < strs.length; j++ ) {

        		//判断是否已经越界，如已经越界就结束循环
        		if( i > strs[j].length() ) {
        			next = false;
        			break;
        		}

        		//判断是否相同
        		if( strs[ 0 ].length() < i || strs[ 0 ].charAt(i-1) != strs[ j ].charAt(i-1) ){
        			next = false;
        			break;
        		}

        		
        	}
        	
        	//根据前面的结果，判断是否将当前位置的字符添加在结果中
        	if( next )
        	    output += strs[ 0 ].charAt(i-1) +"";

        	i++;
    	}
    	
		return output;
        
    }
}

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1. Source: stay button (LeetCode)
   link: https: //leetcode-cn.com/problems/longest-common-prefix
   copyrighted by deduction from all networks. Commercial reprint please contact the authorized official, non-commercial reprint please indicate the source. ↩︎