14 Longest Common Prefix

Author: int32bit

README.md

@@ -8,6 +8,7 @@
 + [9 Palindrome Number](algorithms/PalindromeNumber)
 + [10 Regular Expression Matching(递归)](algorithms/RegularExpressionMatching)
 + [11 Container With Most Water](algorithms/ContainerWithMostWater)
++ [14 Longest Common Prefix](algorithms/LongestCommonPrefix)
 + [15 3Sum](algorithms/3Sum)
 + [17 Letter Combinations of a Phone Number](algorithms/LetterCombinationsofaPhoneNumber)
 + [18 4Sum](algorithms/4Sum)

algorithms/LongestCommonPrefix/README.md

@@ -0,0 +1,23 @@
+## Longest Common Prefix
+
+Write a function to find the longest common prefix string amongst an array of strings.
+
+## Solution
+
+逐一比较即可
+```cpp
+string longestCommonPrefix(vector<string>& strs) {
+    int n = strs.size();
+    if (n < 1)
+	    return "";
+    int m = strs[0].size();
+    int i,j;
+    for (i = 0; i < m; ++i) {
+	    for (auto s : strs) {
+		    if (i >= s.size() || s[i] != strs[0][i])
+			    return strs[0].substr(0, i);
+	    }
+    }
+    return strs[0];
+}
+```

algorithms/LongestCommonPrefix/solve.cpp

@@ -0,0 +1,29 @@
+#include <string>
+#include <iostream>
+#include <cstdio>
+#include <vector>
+using namespace std;
+class Solution {
+public:
+    string longestCommonPrefix(vector<string>& strs) {
+	    int n = strs.size();
+	    if (n < 1)
+		    return "";
+	    int m = strs[0].size();
+	    int i,j;
+	    for (i = 0; i < m; ++i) {
+		    for (auto s : strs) {
+			    if (i >= s.size() || s[i] != strs[0][i])
+				    return strs[0].substr(0, i);
+		    }
+	    }
+	    return strs[0];
+    }
+
+};
+int main(int argc, char **argv)
+{
+	Solution solution;
+	vector<string> s = {"abcd", "abc", "abedefg", "abcdefgh"};
+	cout << solution.longestCommonPrefix(s) << endl;
+}