soj 3014: Seek the Name, Seek the Fame (字符串hash)

#include <cstdio>
#include <iostream>
#include <cstring>
#include <cstdlib>
#include <string>
#include <vector>
#include <set>
#include <map>
#include <queue>
#include <algorithm>
using namespace std;
const int maxn = 4e5 + 123, INF = 0x3fffffff, mod = 1e9 + 7;
typedef int ull;
char s[maxn];
int slen, seed = 131;

int main(void ){
while (~scanf("%s", s)) {
slen = (int)strlen(s);
ull a = 0, b = 0, x = 1;
bool first = false;
for (int i = 0, j = slen - 1; i < slen; i++, j--) {
a = (s[i] - 'a' + 1) + a * seed;
b = b + (s[j] - 'a' + 1) * x;
if (a == b) {
if (first) printf(" ");
else first = true;
printf("%d", i + 1);
}
x *= seed;
}
printf("\n");
}
return 0;
}