中国剩余定理

C++模数逆元求解

最新推荐文章于 2024-12-25 18:28:40 发布

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最新推荐文章于 2024-12-25 18:28:40 发布

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原文链接：http://www.cnblogs.com/kcfzyhq/p/8857706.html

#include<bits/stdc++.h>
#define ll long long
#define gc getchar
inline ll read(){ll x = 0; char ch = gc(); bool positive = 1;for (; !isdigit(ch); 
ch = gc()) if (ch == '-')  positive = 0;for (; isdigit(ch); ch = gc())  x = x * 10 
+ ch - '0';return positive ? x : -x;}inline void write(ll a){if(a>=10)write(a/10);
putchar('0'+a%10);}inline void writeln(ll a){if(a<0){a=-a; putchar('-');}write(a);
puts("");}
using namespace std;
const int N = 11;
ll l,r,n;
ll m[N], M = 1,a[N], Mi;
void exgcd(ll a,ll b,ll &x , ll &y) {
    if(b) {
        exgcd(b, a % b, y, x);
        y -= a / b * x;
    }else {
        x = 1;
        y = 0;
    }
}
int main() {
    ll x, y, res = 0, ans = 0;
    n = read(), l = read(),r = read();
    for(int i = 1; i <= n; ++i)
        m[i] = read(), a[i] = read(), M *= m[i];
    for(int i = 1; i <= n; ++i) {
        Mi = M / m[i];
        exgcd(Mi, m[i], x, y);
        x = (x % m[i] + m[i]) % m[i];
        res = res + a[i] * Mi * x ;
    }
    res %= M;
    if(!res) res += M;
    if(res < l) res += (l - res - 1) / M * M + M;
    if(res <= r) ans = (r - res - 1) / M + 1;
    if(!ans) {
        puts("0\n0");
        return 0;
    }
    writeln(ans);
    writeln(res);
    return 0;
}

转载于:https://www.cnblogs.com/kcfzyhq/p/8857706.html