[LintCode] Longest Common Prefix 最长共同前缀

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Given k strings, find the longest common prefix (LCP).

Have you met this question in a real interview?

Example

For strings "ABCD", "ABEF" and "ACEF", the LCP is "A"

For strings "ABCDEFG", "ABCEFG" and "ABCEFA", the LCP is "ABC"

LeetCode上的原题，请参见我之前的博客Longest Common Prefix。

解法一：

class Solution {
public:
/**
* @param strs: A list of strings
* @return: The longest common prefix
*/
string longestCommonPrefix(vector<string> &strs) {
if (strs.empty()) return "";
string res = "";
for (int j = ; j < strs[].size(); ++j) {
char c = strs[][j];
for (int i = ; i < strs.size(); ++i) {
if (j >= strs[i].size() || strs[i][j] != c) return res;
}
res.push_back(c);
}
return res;
}
};

解法二：

class Solution {
public:
/**
* @param strs: A list of strings
* @return: The longest common prefix
*/
string longestCommonPrefix(vector<string> &strs) {
if (strs.empty()) return "";
for (int j = ; j < strs[].size(); ++j) {
for (int i = ; i < strs.size() - ; ++i) {
if (j >= strs[i].size() || j >= strs[i + ].size() || strs[i][j] != strs[i + ][j]) {
return strs[i].substr(, j);
}
}
}
return strs[];
}
};