1093.Count PAT's (25)...to be continued...

/**
* pat-al-1093
* 2017-03-02
* Cpp version
* Author: fengLian_s
*/
#include<stdio.h>
#include<string.h>
#define MAX 100010
int main()
{
freopen("in.txt", "r", stdin);
char str[MAX];
scanf("%s", str);
int numOfP[MAX] = {0};
int len = strlen(str);
for(int i = 0;i < len;i++)
{
if(i > 0 && str[i] == 'P')
{
numOfP[i] = numOfP[i-1]+1;
}
else if(i == 0 && str[i] == 'P')
{
numOfP[i] = 1;
}
else
numOfP[i] = numOfP[i-1];
//printf("i: %d\n", numOfP[i]);
}
int numOfT = 0;
int ans = 0;
for(int i = len-1;i >= 0;i--)
{
if(i == len-1 && str[i] == 'T')
numOfT = 1;
else if(i < len-1 && str[i] == 'T')
numOfT++;
else if(str[i] == 'A')
{
ans += (numOfT * numOfP[i]);
ans %= 1000000007;
}
}
printf("%d\n", ans);
return 0;
}