参考答案

参考回答:

int substr(string & str1, string &str2)
{
int len1 = str1.length();
int len2 = str2.length();
vector<vector<int>>dp(len1,vector<int>(len2,0));
for (int i = 0; i < len1; i++)
{
dp[i][0] = str1[i]==str2[0]?1:0;
}
for (int j = 0; j <= len2; j++)
{
dp[0][j] = str1[0]==str2[j]?1:0;
}
for (int i = 1; i < len1; i++)
{
for (int j = 1; j < len2; j++)
{
if (str1[i] == str2[j])
{
dp[i][j] = dp[i - 1][j - 1]+1;
}
}
}
int longest = 0;
int longest_index = 0;
for (int i = 0; i < len1; i++)
{
for (int j = 0; j < len2; j++)
{
if (longest < dp[i][j])
{
longest = dp[i][j];
longest_index = i;
}
}
}

//字符串为从第i个开始往前数longest个

for (int i = longest_index-longest+1; i <=longest_index; i++)
{
cout << str1[i] << endl;
}
return longest;
}