数据结构练习（34）对称子字符串的最大长度

http://zhedahht.blog.163.com/blog/static/25411174201063105120425/

思路：

最简单的区间dp思想。

#include <iostream>

using namespace std;



int dp[100][100];



int solve(const char* s)

{

    if (s == nullptr)

        return -1;



    int maxvalue = 1;

    int len = strlen(s);



    memset(dp, 0, sizeof(dp));



    for (int i = 0; i < len; ++i)

    {

        dp[i][i] = 1;

        if (i + 1 < len && s[i] == s[i+1])

            dp[i][i+1] = 2;

    }



    for (int d = 2; d < len; ++d)

    {

        for (int i = 0, j = d; j < len; ++i, ++j)

        {

            if (s[i] == s[j] && dp[i+1][j-1])

                dp[i][j] = dp[i+1][j-1] + 2;

            if (maxvalue < dp[i][j])

                maxvalue = dp[i][j];

        }

    }

    return maxvalue;

}



int main()

{

    char b[100] = "google";

    cout << solve(b) << endl;

    return 0;

}