poj传送门 裸的中国剩余定理，注意一下负数的情况即可
#include<cstdio> #include<algorithm> #include<cstring> #define ms(i,j) memset(i,j, sizeof i); #define ll long longusing namespace std;int p, e, i, d;int a[4],m[4];void e_gcd(int a, int b, int &x, int &y){ if (b==0) { x=1; y=0; return ; } e_gcd(b,a%b,x,y); int t = x; x = y; y = t-y*a/b;}int crt(int n){ int ans = 0; int M = 1; for (int i=1;i<=n;i++) M*=m[i]; for (int i=1;i<=n;i++) { int Mi = M/m[i]; int x,y; e_gcd(Mi, m[i], x, y); ans = (ans + Mi*a[i]*x)%M; } return (ans+M)%M;}int main() { int kase = 0; m[1] = 23;m[2] = 28;m[3] = 33; while (scanf("%d%d%d%d", &p, &e, &i, &d)==4) { if(p == -1 && e == -1 && i == -1 && d == -1) break; a[1] = p; a[2] = e; a[3] = i; int ans = crt(3); ans -= d; if (ans<=0) ans += 21252; PRintf("Case %d: the next triple peak occurs in %d days./n", ++kase, ans); } return 0; }新闻热点
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