埃及分数问题

#include<cstdio>
#include<algorithm>
#include<cstring>
using namespace std;
#define long long LL


bool dfs(int d,int from,LL aa, LL bb){
    if(d == maxd){
        if(bb%aa) return false;
        v[d] = bb/aa;
        if(better(d)) memccpy(ans, v, sizeof(LL)*(d+1));
    }
    bool ok =false;
    from=max(from, get_fitst(aa,bb));
    for(int i=from;;i++){
        ///减枝：如果剩下的maxd+1-d个分数全部是1/i，加起来仍然不超过aa/bb，则无解
        if(bb * (maxd+1-d) <= i*aa) break;
        v[d]=i;
        ///计算aa/bb - 1/i,设结果为a2/b2
        LL b2 = bb*i;
        LL a2 = aa*i - bb;
        LL g = gcd(a2,b2);
        if(dfs(d+1,i+1,a2/g,b2/g)) ok =true;
    }
    return ok;
}
int main()
{
    int ok=0;
    for(int maxd=1;;maxd++){
        memset(ans,-1,sizeof(ans));
        if(dfs(0,get_first(a,b), a, b)) { ok=1;break; }
        ///其中get_first(a,b)是满足1/c <= a/b的最小c
    }
    return 0;
}