zoj2744 Palindromes

ZOJ Problem Set - 2744

Palindromes

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Time Limit: 1 Second      Memory Limit: 32768 KB

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A regular palindrome is a string of numbers or letters that is the same forward as backward. For example, the string "ABCDEDCBA" is a palindrome because it is the same when the string is read from left to right as when the string is read from right to left.

Now give you a string S, you should count how many palindromes in any consecutive substring of S.

Input

There are several test cases in the input. Each case contains a non-empty string which has no more than 5000 characters.

Proceed to the end of file.

Output

A single line with the number of palindrome substrings for each case.

Sample Input

aba
aa

Sample Output

4
3

Author: LIU, Yaoting

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Source: Zhejiang Provincial Programming Contest 2006
Submit    Status

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//1843510 2009-04-25 09:07:35 Memory Limit Exceeded  2744 C++ 0 32769 Wpl
//1843514 2009-04-25 09:21:07 Time Limit Exceeded  2744 C++ 1001 24612 Wpl
//1843524 2009-04-25 09:39:08 Accepted  2744 C++ 760 24612 Wpl 
/*
最好边做边计算sum如果单独出来计算会超时
*/
#include <iostream>
#define MAX 5001
using namespace std;
bool mark[MAX][MAX];
char str[MAX];
int main()
{
 int i,j,len,r;
 while(scanf("%s",str+1)!=EOF)
 {
  int sum=0;
  len=strlen(str+1);
  for(r=1;r<=len;r++)
   for(i=1;i<=len-r+1;i++)
   {
    j=i+r-1;
    if(i==j)  //注意将这种情况统计在里面
    {
     mark[i][j]=1;
     sum++;
     continue;
    }
    if(j==i+1&&str[i]==str[j]) //注意将这种情况统计在里面
    {
     mark[i][j]=1;
     sum++;
     continue;
    }
    mark[i][j]=0;
    if(str[i]!=str[j])
     mark[i][j]=0;
    else
    {
     if(mark[i+1][j-1])
     {
      mark[i][j]=1;
      sum++;
     }
     else
      mark[i][j]=0;
    }
   }
  printf("%d\n",sum);
 }
 return 0;
}