洛谷P2485 [SDOI2011]计算器

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#include <map>
#include <cmath>
#include <cstdio>
#include <algorithm>
#define LL long long
#define gc() getchar()
#define rep(i, a, b) for(int i = (a); i <= (b); ++i)
using namespace std;
const int N = 1e8 + 5;
LL t, x, y, z, k, gg;
LL X1, Y1;
map <LL, LL> c;

inline int read() {
	char ch = gc();
	int ans = 0;
	while (ch > '9' || ch < '0') ch = gc();
	while (ch >= '0' && ch <= '9') ans = (ans << 1) + (ans << 3) + ch - '0', ch = gc();
	return ans;
}

inline LL quick_pow(LL a, LL b, LL p) {
	LL base = a, ans = 1;
	while (b) {
		if (b & 1) ans = (ans * base) % p;
		base = (base * base) % p;
		b >>= 1;
	}
	return ans;
} 

inline void exgcd(int a, int b) {
	if (!b) { gg = a; X1 = 1, Y1 = 0; return; }
	exgcd(b, a % b);
	int temp = X1;
	X1 = Y1, Y1 = temp - a / b * Y1;	
}

int main() {
	t = read(), k = read();
	if (k == 1) {
		while(t--) {
			int p;
			y = read(), z = read(), p = read();
			printf("%lld
", quick_pow(y, z, p)); 
		}
	}
	else if (k == 2) {
		while (t--) {
			int p;
			y = read(), z = read(), p = read();
			exgcd(y, p);
			if (z % gg) { printf("Orz, I cannot find x!
"); continue; }
			X1 = X1 * (z / gg);
			if (X1 > 0 && X1 % p) X1 = X1 - (X1 / p) * p;
			else if (X1 < 0) {
				if ((0 - X1) % p) X1 = X1 + ((0 - X1) / p + 1) * p;
				else X1 = 0;
			}
			printf("%lld
", X1);
		} 
	}
	else {
		while (t--) {
			int p;
			y = read(), z = read(), p = read();
			if (z && y % p == 0) { printf("Orz, I cannot find x!
"); continue; }
			x = ceil(sqrt(p));
			c.clear();
			LL cur = z % p, po = quick_pow(y, x, p);
			c[cur] = 0;
			rep(i, 1, x) cur = (cur * y) % p, c[cur] = i;
			cur = 1;
			int vis = 1;
			rep(i, 1, x) {
				cur = (cur * po) % p;
				if (c[cur]) { X1 = (i * x - c[cur]) % p; printf("%lld
", (X1 + p) % p); vis = 0; break; }
			}
			if (vis) printf("Orz, I cannot find x!
");
		} 
	}
	return 0;
}