# BZOJ 2242: [SDOI2011]计算器

2242

#include<bits/stdc++.h>
using namespace std;
#define fi first
#define se second
#define pi acos(-1.0)
#define LL long long
//#define mp make_pair
#define pb push_back
#define ls rt<<1, l, m
#define rs rt<<1|1, m+1, r
#define ULL unsigned LL
#define pll pair<LL, LL>
#define pii pair<int, int>
#define piii pair<int,pii>
#define mem(a, b) memset(a, b, sizeof(a))
#define fio ios::sync_with_stdio(false);cin.tie(0);cout.tie(0);
#define fopen freopen("in.txt", "r", stdin);freopen("out.txt", "w", stout);

map<int, int>mp;
LL q_pow(LL n, LL k, LL p) {
LL ans = 1;
if(k == -1) return 0;
while(k) {
if(k&1) ans = (ans*n) % p;
n = (n*n) % p;
k >>= 1;
}
return ans;
}

int BSGS(int a, int b, int c) {
if(a%c == 0 && b%c != 0 ) return -1;
int m = ceil(sqrt(c)), base = 1;
mp.clear();
for (int i = 0; i < m; i++) {
if(mp.find(base) == mp.end()) mp[base] = i;
base = (1LL * base * a) % c;
}
int D = 1;
for (int i = 0; i < m; i++) {
int x = (b * q_pow(D, c - 2, c)) % c;
if(mp.find(x) != mp.end()) return i*m + mp[x];
D = (1LL * D * base) % c;
}
return -1;
}
int main() {
int T, op, y, z, p;
while( ~scanf("%d %d", &T, &op)) {
for (int i = 1; i <= T; i++) {
scanf("%d %d %d", &y, &z, &p);
if(op == 1) {
printf("%lld\n", q_pow(y, z, p));
}
else if(op == 2) {
if(y%p == 0 && z%p != 0) printf("Orz, I cannot find x!\n");
else printf("%lld\n", (1LL* z * q_pow(y, p-2, p)) % p);
}
else if(op == 3) {
int ans = BSGS(y, z, p);
if(ans == -1) printf("Orz, I cannot find x!\n");
else printf("%d\n", ans);
}
}
}
return 0;
}

posted @ 2018-07-07 11:28  Wisdom+.+  阅读(158)  评论(0编辑  收藏  举报