longest_common_prefix.cpp

Author: jakoo

longest_common_prefix.cpp

@@ -0,0 +1,34 @@
+class Solution {
+public:
+    string longestCommonPrefix(vector<string>& strs) {
+        if (strs.size() == 0)
+            return string();
+        if (strs.size() == 1)
+            return strs[0];
+        int minLen = longestCommonPrefix(strs[0], strs[1], -1);
+        for (auto vit = strs.begin() + 1, nextit = strs.begin() + 2;
+            nextit != strs.end(); ++vit, ++nextit)
+        {
+            int len = longestCommonPrefix(*vit, *nextit, minLen);
+            if (len < minLen)
+                minLen = len;
+        }
+            
+        
+        return string(strs[0], 0, minLen);
+    }
+    
+    int longestCommonPrefix(string& str1, string& str2, int len)
+    {
+        int result = 0;
+        auto sit1 = str1.begin(), sit2 = str2.begin();
+        for(int i = 0;
+            sit1 != str1.end() && sit2 != str2.end() && 
+            *sit1 == *sit2 && (i < len || len == -1); 
+            ++sit1, ++sit2)
+        {
+            ++result;
+        }
+        return result;
+    }
+};