Submission #12162

#	Time	Username	Problem	Language	Result	Execution time	Memory
12162		xhae	Min-cost GCD (GA9_mcg)	C++14	57 / 100	1000 ms	1580 KiB

mcg

#include <unordered_map>
#include <cstdio>
#include <algorithm>

using namespace std;

class llhash
{
	public:
		size_t operator()(const pair<long long, long long>& x) const
		{
			size_t h = (x.first << 48) | ((x.second << 48) >> 48);
			return h;
		}
};

unordered_map<pair<long long, long long>, long long, llhash> dp;

long long a, b, p, q;
const long long INF = 1000000ll * 1000000ll * 500000ll;
 
long long getAns(long long a, long long b)
{
    if(a == 0 || b == 0) return 0;
 
    pair<long long, long long> cur = make_pair(a, b);
    if(dp.count(cur)) return dp[cur];
     
    long long ret = p + getAns(b, a % b);
 
    if(a >= b)
    {
        long long howMany = a / b;
        if(howMany <= ret / (double)q)
        {
            long long cand = howMany * q + getAns(a % b, b);
            ret = min(cand, ret);
        }
    }
    else
    {
        long long howMany = b / a;
        if(howMany <= ret / (double)q)
        {
            long long cand = howMany * q + getAns(a, b % a);
            ret = min(cand, ret);
        }
    }
 
    return dp[cur] = ret;
}
 
int main(void)
{
    int T;
    scanf("%d", &T);
    while(T--)
    {
        scanf("%lld %lld %lld %lld", &a, &b, &p, &q);
        dp.clear();
        printf("%lld\n", getAns(a, b));
    }
 
    return 0;
}

• Subtask 1: 14 / 14
• Subtask 2: 16 / 16
• Subtask 3: 27 / 27
• Subtask 4: 0 / 43