HDU 1452 Happy 2004 数论

#include <iostream>
#include <cstdio>
#include <string>
#include <vector>
#include <cstring>
#include <iterator>
#include <cmath>
#include <algorithm>
#include <stack>
#include <deque>
#include <map>
#define lson l, m, rt<<1
#define rson m+1, r, rt<<1|1
#define mem0(a) memset(a,0,sizeof(a))
#define sca(x) scanf("%d",&x)
#define de printf("=======\n")
typedef long long ll;
using namespace std;

const int mod = 29;
ll q_power( ll a, ll b ) {
    ll ret = 1;
    while( b ) {
        if( b & 1 ) ret = ret * a % mod;
        b >>= 1;
        a = a * a % mod;
    }
    return ret % mod;
}
ll exgcd(ll a, ll b, ll &x, ll &y) {
    if(b == 0) {
        x = 1;
        y = 0;
        return a;
    }
    else {
        ll ret = exgcd(b, a%b, x, y);
        ll tmp = x;
        x = y;
        y = tmp - a / b * y;
        return ret;
    }
}
ll inv(ll a) {
    ll x, y;
    exgcd(a, mod, x, y);
    return (x % mod + mod) % mod;
}
int main() {
    ll x;
    while( scanf( "%lld", &x ) == 1 && x ) {
        ll ans;
        ll a = q_power(3, x+1);
        ll b = q_power(167, x+1);
        ll c = q_power(2, 2*x+1);
        ans = (a*b*c-a*c-b*c+c-a*b+a+b-1) * inv(332) % mod;
        printf( "%lld\n", ans );
    }
    return 0;
}