孙子定理百度内容:https://baike.baidu.com/item/孙子定理/2841597?fromtitle=中国剩余定理&fromid=11200132&fr=aladdin
孙子定理及其扩展:https://blog.csdn.net/clove_unique/article/details/54571216/
hdu 1573扩展中国剩余定理:https://blog.csdn.net/clove_unique/article/details/54427430
hdu5446题目:https://vjudge.net/problem/HDU-5446
ac代码:
#include <cstdio>
#include <cstring>
#include <algorithm>
using namespace std;
typedef long long ll;
const int maxn = 1e5 + 5;
ll fac[maxn], inv[maxn];
ll pow_mod(ll a, int n, int mod) {
ll ret = 1;
while (n) {
if (n&1) ret = ret * a % mod;
a = a * a % mod;
n >>= 1;
}
return ret;
}
void init(int n) {
fac[0] = 1;
for (int i = 1; i < n; i++) fac[i] = fac[i-1] * i % n;
inv[n-1] = pow_mod(fac[n-1], n-2, n);
for (int i = n - 2; i >= 0; i--) inv[i] = inv[i+1] * (i+1) % n;
}
ll C (int n, int m, int mod) {
if (m > n || m < 0 || n < 0) return 0;
return fac[n] * inv[m] % mod * inv[n-m] % mod;
}
ll lucas(ll n, ll m, int mod) {
if (m == 0) return 1;
return lucas(n / mod, m / mod, mod) * C(n % mod, m % mod, mod) % mod;
}
ll exgcd(ll a, ll b, ll& x, ll& y) {
if (b == 0) { x = 1; y = 0; return a; }
ll d = exgcd(b, a % b, y, x);
y -= x * (a / b);
return d;
}
ll mul(ll a, ll b, ll mod) {
a = (a % mod + mod) % mod;
b = (b % mod + mod) % mod;
ll ret = 0;
while(b){
if(b&1){
ret += a;
if(ret >= mod) ret -= mod;
}
b >>= 1;
a <<= 1;
if(a >= mod) a -= mod;
}
return ret;
}
ll china(int n, ll* a, ll* m) {
ll M = 1, d, y, x = 0;
for (int i = 0; i < n; i++) M *= m[i];
for (int i = 0; i < n; i++) {
ll w = M / m[i];
exgcd(m[i], w, d, y);
x = (x + mul(mul(y, w, M), a[i], M));
}
return (x + M) % M;
}
int main () {
int cas, k;
ll n, m, a[15], p[15];
scanf("%d", &cas);
while (cas--) {
scanf("%lld%lld%d", &n, &m, &k);
for (int i = 0; i < k; i++) {
scanf("%lld", &p[i]);
init(p[i]);
a[i] = lucas(n, m, p[i]);
}
printf("%lld\n", china(k, a, p));
}
return 0;
}
#include <iostream>
#include <cstdio>
#include <cstring>
#include <vector>
#include <queue>
using namespace std;
typedef long long ll;
ll p[15],an[15];
ll fac[100005],inv[100005];
ll pow_mod(ll a, int n, int mod)
{
ll ret = 1;
while (n)
{
if (n&1) ret = ret * a % mod;
a = a * a % mod;
n >>= 1;
}
return ret;
}
void ini(int x)
{
fac[0] = 1;
for(int i = 1; i < x; i++) fac[i] = fac[i-1]*i%x;
inv[x - 1] = pow_mod(fac[x-1],x-2,x);
for(int i = x - 2; i >= 0; i--) inv[i] = inv[i+1] * (i+1) % x;
}
ll c(ll a,ll b,ll p)
{
if(a < b || a < 0 || b < 0)
return 0;
return fac[a]*inv[b]%p*inv[a-b]%p;
}
ll lucas(ll a,ll b, int p)
{
if( b == 0)
return 1;
return lucas(a/p,b/p,p)*c(a%p,b%p,p)%p;
}
ll ex_gcd(ll a, ll b, ll& x, ll& y)
{
if (b == 0)
{
x = 1;
y = 0;
return a;
}
ll d = ex_gcd(b, a % b, y, x);
y -= x * (a / b);
return d;
}
ll mul(ll a, ll b, ll mod)
{
a = (a % mod + mod) % mod;
b = (b % mod + mod) % mod;
ll ret = 0;
while(b)
{
if(b&1)
{
ret += a;
if(ret >= mod) ret -= mod;
}
b >>= 1;
a <<= 1;
if(a >= mod) a -= mod;
}
return ret;
}
ll china(ll n,ll* a,ll* b)
{
ll M = 1,d,y,x= 0;
for(int i = 0; i < n; i++)
{
M *= b[i];
}
for(int i = 0; i < n; i++)
{
ll w = M/b[i];
ex_gcd(b[i],w,d,y);
x = (x + mul(mul(y, w, M), a[i], M));//可能超范围
}
return (x+M) % M;
}
int main()
{
int T,k;
ll n,m;
scanf("%d",&T);
while(T--)
{
scanf("%I64d%I64d",&n,&m);
scanf("%d",&k);
for(int i = 0; i < k; i++)
{
scanf("%I64d",&p[i]);
ini(p[i]);
an[i] = lucas(n,m,p[i]);
}
printf("%I64d\n",china(k,an,p));
}
return 0;
}