更新 Solution.java

src/solution/Solution.java

@@ -106,33 +106,55 @@ public class Solution {
         System.out.println(result);
     }
 
+//    public static String longestCommonPrefix(String[] strs) {
+//        int index = 0;
+//        StringBuilder temp = new StringBuilder();
+//        if (strs != null){
+//            for (int k = 0; k < strs[0].length(); k++) {
+//                char indexChar = strs[0].charAt(index);
+//                if (strs.length == 1){
+//                    return strs[0];
+//                }
+//                for (int i = 1; i < strs.length; i++) {
+//                    if (strs[i] != ""){
+//                        for (int j = 0; j < 1; j++) {
+//                            if (index >= strs[i].length()){
+//                                return String.valueOf(temp);
+//                            }
+//                            char crrChar = strs[i].charAt(index);
+//                            if (indexChar != crrChar){
+//                                return String.valueOf(temp);
+//                            }
+//                            if (i == strs.length- 1){
+//                                temp.append(crrChar);
+//                                index++;
+//                            }
+//                        }
+//                    } else {
+//                        return "";
+//                    }
+//                }
+//            }
+//            return String.valueOf(temp);
+//        }
+//        return "";
+//    }
+
     public static String longestCommonPrefix(String[] strs) {
-        // ["flower","flow","flight"]
-        int maxPrefix = 0;
-        int index = 0;
-        StringBuilder temp = new StringBuilder();
-        if (strs != null){
-            for (int k = 0; k < strs[0].length(); k++) {
-                char indexChar = strs[0].charAt(index);
-                for (int i = 1; i < strs.length; i++) {
-                    if (strs[i] != ""){
-                        for (int j = 0; j < 1; j++) {
-                            char crrChar = strs[i].charAt(index);
-                            if (indexChar != crrChar){
-                                return String.valueOf(temp);
-                            }
-                            if (i == strs.length- 1){
-                                temp.append(crrChar);
-                                index++;
-                            }
-                        }
-                    } else {
-                        return "";
-                    }
+        if (strs == null || strs.length == 0) {
+            return "";
+        }
+        int length = strs[0].length();
+        int count = strs.length;
+        for (int i = 0; i < length; i++) {
+            char c = strs[0].charAt(i);
+            for (int j = 1; j < count; j++) {
+                if (i == strs[j].length() || strs[j].charAt(i) != c) {
+                    return strs[0].substring(0, i);
                 }
             }
-
         }
-        return "";
+        return strs[0];
     }
+
 }

src/solution/test.java

@@ -18,7 +18,7 @@ public class test {
 //        int n = 0;
 //        Solution.merge(nums1,m,nums2,n);
 //        String[] strs = new String[]{"flower","flow","flight"};
-        String[] strs = new String[]{"abcg","abcecar","abr"};
+        String[] strs = new String[]{"flower","flower","flower","flower"};
 
         String result =  Solution.longestCommonPrefix(strs);
         System.out.println(result);