洛谷P2485 [SDOI2011]计算器

待补锅...

#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\n", 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!\n"); 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\n", X1);
        } 
    }
    else {
        while (t--) {
            int p;
            y = read(), z = read(), p = read();
            if (z && y % p == 0) { printf("Orz, I cannot find x!\n"); 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\n", (X1 + p) % p); vis = 0; break; }
            }
            if (vis) printf("Orz, I cannot find x!\n");
        } 
    }
    return 0;
} 

原文地址：https://www.cnblogs.com/Miraclys/p/12422938.html