Submission #3226187


Source Code Expand

/*
结论题Orz

设$f(x, y)$表示$(x, y)$辗转相除需要的步数,$fib(i)$表示第$i$个斐波那契数

常识:$f(fib[i], fib[i+1]) = i$。

定义一个数对是“好的”,当且仅当对于$(x, y)$,不存在更小的$x', y'$使得$f(x', y') > f(x, y)$

显然我们需要统计的数对一定是好的数对

定义一个数对是“优秀的”,当且仅当对于$(x, y)$,若$f(x, y) = k$, 满足$x, y \leqslant fib[k+2] + fib[k-1]$

结论!:一个好的数对辗转相除一次后一定是优秀的数对!

证明可以用反证法,也就是我先假设一个$f(a, b) = i$是好的,但是得到的数对$(x, y)$满足$y > fib[k+2] + fib[k-1]$

但是这样我们会得到一个$x' = f[i+2], y' = f[i+2]$满足$f(x', y')>f(a, b)$,所以不成立

那么现在要做的就是求“优秀的”数对的个数。

考虑直接用欧几里得算法的定义递推即可

*/
#include<iostream>
#include<cstdio>
#include<algorithm>
#include<vector>
#define Pair pair<LL, LL> 
#define MP(x, y) make_pair(x, y)
#define fi first 
#define se second 
#define LL long long 
#define int long long 
using namespace std;
const int MAXN = 1e6 + 10, B = 90, mod = 1e9 + 7;
inline LL read() {
	char c = getchar(); LL x = 0, f = 1;
	while(c < '0' || c > '9') {if(c == '-') f = -1; c = getchar();}
	while(c >= '0' && c <= '9') x = x * 10 + c - '0', c = getchar();
	return x * f;
}
vector<Pair> v[B + 1];
LL f[B + 1];
void Pre() {
	f[0] = f[1] = 1;
	for(int i = 2; i <= B; i++) f[i] = f[i - 1] + f[i - 2];
	v[1].push_back(MP(1, 2)); v[1].push_back(MP(1, 3)); v[1].push_back(MP(1, 4));
	for(int i = 1; i <= B - 3; i++) {
		for(int j = 0; j < v[i].size(); j++) {
			LL x = v[i][j].fi, y = v[i][j].se;
			LL tmp = x; x = y; y = tmp + y;
			while(y <= f[i + 3] + f[i - 1]) v[i + 1].push_back(MP(x, y)), y += x;
		}
	}
}
main() {
	// freopen("1.in", "r", stdin);
	Pre();
	int Q = read();
	while(Q--) {
		LL x = read(), y = read(), K;
		if(x > y) swap(x, y);
		for(K = 1; f[K + 1] <= x && f[K + 2] <= y; K++);
		cout << K << " ";
		if(K == 1) {cout << x * y % mod << endl; continue;}
		LL ans = 0;
		for(int i = 0; i < v[K - 1].size(); i++) {
			LL a = v[K - 1][i].fi, b = v[K - 1][i].se;
		//	printf("%I64d %I64d\n", a, b);
			if(b <= x) ans += (y - a) / b % mod;
			if(b <= y) ans += (x - a) / b % mod;
			//if(a + b <= x && b <= y) ans++;
			//if(a + b <= y && a <= x) ans++;
			ans %= mod;
		}
		cout << ans % mod<< endl;
	}
	return 0;
}
/*
1
12 11
*/

Submission Info

Submission Time
Task F - Kenus the Ancient Greek
User attack
Language C++14 (GCC 5.4.1)
Score 1700
Code Size 2550 Byte
Status AC
Exec Time 1053 ms
Memory 4096 KB

Judge Result

Set Name Sample All
Score / Max Score 0 / 0 1700 / 1700
Status
AC × 2
AC × 26
Set Name Test Cases
Sample s1.txt, s2.txt
All 01.txt, 02.txt, 03.txt, 04.txt, 05.txt, 06.txt, 07.txt, 08.txt, 09.txt, 10.txt, 11.txt, 12.txt, 13.txt, 14.txt, 15.txt, 16.txt, 17.txt, 18.txt, 19.txt, 20.txt, 21.txt, 22.txt, 23.txt, 24.txt, s1.txt, s2.txt
Case Name Status Exec Time Memory
01.txt AC 747 ms 3328 KB
02.txt AC 751 ms 3328 KB
03.txt AC 735 ms 3328 KB
04.txt AC 752 ms 3328 KB
05.txt AC 740 ms 3328 KB
06.txt AC 734 ms 3328 KB
07.txt AC 737 ms 3328 KB
08.txt AC 734 ms 3328 KB
09.txt AC 735 ms 3328 KB
10.txt AC 743 ms 3328 KB
11.txt AC 1049 ms 1920 KB
12.txt AC 1053 ms 1920 KB
13.txt AC 632 ms 1920 KB
14.txt AC 627 ms 1920 KB
15.txt AC 671 ms 4096 KB
16.txt AC 702 ms 4096 KB
17.txt AC 552 ms 3840 KB
18.txt AC 567 ms 3840 KB
19.txt AC 951 ms 3584 KB
20.txt AC 969 ms 3584 KB
21.txt AC 1 ms 384 KB
22.txt AC 1 ms 384 KB
23.txt AC 1 ms 384 KB
24.txt AC 1 ms 384 KB
s1.txt AC 1 ms 384 KB
s2.txt AC 1 ms 384 KB