可删除某些字符的最长回文字符串(2016腾讯在线笔试题)

#include"stdafx.h"
#include<iostream>
#include<stdlib.h>
#include<stdio.h>

using namespace std;

int Length_record[1000][1000];

int max(int a, int b)
{
return a > b ? a : b;
}

int number_of_reverse(char* str, int start, int end, int crruentLength, int &max_Length)
{
if (Length_record[start][end] != -1)
{
if (crruentLength + Length_record[start][end] > max_Length)
max_Length = crruentLength + Length_record[start][end];
return Length_record[start][end];
}
if (Length_record[start][end] == -1)
{
if (start == end)
{
crruentLength++;
if (crruentLength > max_Length)
max_Length = crruentLength;
Length_record[start][end] = 1;
}
if (end - start == 1)
{
if (str[start] == str[end])
{
crruentLength += 2;
Length_record[start][end] = 2;
}
else
{
crruentLength++;
Length_record[start][end] = 1;
}
if (crruentLength > max_Length)
max_Length = crruentLength;
}
if (end - start > 1)
{
if (str[end] == str[start])
Length_record[start][end]=2+number_of_reverse(str, start + 1, end - 1, crruentLength + 2, max_Length);
else
{
Length_record[start][end] =max( number_of_reverse(str, start, end - 1, crruentLength, max_Length), number_of_reverse(str, start + 1, end, crruentLength, max_Length));
}
}
}
return Length_record[start][end];

}

int number_of_delete(char *str)
{
if (str == NULL)
cout << "0" << endl;
int nLength = strlen(str);
int max_Length = 0;
number_of_reverse(str, 0, nLength - 1, 0, max_Length);
return max_Length;
}

int main()
{
memset(Length_record, -1, sizeof(Length_record));
char str[1000];
cin >> str;
int a = number_of_delete(str);
cout << a << endl;
}