Count the string (memory-based search)

Count the string Time Limit: 2000/1000 MS (Java/others) memory limit: 32768/32768 K (Java/Others)
Total submission (s): 4899 accepted submission (s): 2313

Question connection

Problem descriptionit is well known that aekdycoin is good at string problems as well as number theory problems. when given a string S, we can write down all the non-empty prefixes of this string. for example:
S: "Abab"
The prefixes are: "A", "AB", "ABA", "Abab"
For each prefix, we can count the times it matches in S. so we can see that prefix "A" matches twice, "AB" matches twice too, "ABA" matches once, and "Abab" matches once. now you are asked to calculate the sum of the match times for all the prefixes. for "Abab", it is 2 + 2 + 1 + 1 = 6.
The answer may be very large, so output the answer MOD 10007.
 
Inputthe first line is a single integer T, indicating the number of test cases.
For each case, the first line is an integer N (1 <= n <= 200000), which is the length of string S. A line follows giving the string S. the characters in the strings are all lower-case letters.
 
Outputfor each case, output only one number: The sum of the match times for all the prefixes of S mod 10007.
Sample Input

14abab

 
Sample output

6

 
Author [email protected]
Sourcehdoj monthly contest-2010.03.06

Memory-based search: records the location of the previous state in advance.

AC code:

#include <iostream>#include <cstring>#include <cstdio>using namespace std;const int M = 1e5 * 2 + 100;char s[M];int map[M];int main(){    int T,n;    scanf("%d",&T);    while(T--)    {        memset(map,0,sizeof(map));        scanf("%d %s",&n,s);        int tp,len,ans;        len = strlen(s);        map[0] = ans = 0;        tp = 1;        for(int i = 1; s[i]; i++)            if(s[i] == s[0]) map[tp++] = i;        ans += tp;        for(map[0]++; map[0] < len; map[0]++)        {            int temp = 1;            for(int i = 1; i < tp; i++)                if(s[map[i] + 1] == s[map[0]]) map[temp++] = map[i] + 1;            tp = temp;            ans += tp;            if(ans > 10007) ans %= 10007;        }        printf("%d\n",ans);    }    return 0;}

 

Count the string (memory-based search)