每日一题 生日快乐(dfs+思维)
[SCOI2009]生日快乐
https://ac.nowcoder.com/acm/problem/20272
思路:我们用dfs去想,首先如果此时只有一个人那我们就直接返回答案,dfs(x,y,n)表示边长为x,y,切给n个人长边与短边之比最大值最小的值是多少,为了保证面积相同每次切若沿着x切必定是x/n的倍数若沿着y切必定是y/n的倍数,我们要看切完后分给多少个人,就看他当前切的是多少倍,然后我们按X,Y去切就行了求他们的最大值最小
#include <cstdio> #include <cstring> #include <algorithm> #include <set> #include<iostream> #include<vector> #include<queue> //#include<bits/stdc++.h> using namespace std; typedef long long ll; #define SIS std::ios::sync_with_stdio(false) #define space putchar(' ') #define enter putchar('\n') #define lson root<<1 #define rson root<<1|1 typedef pair<int,int> PII; const int mod=1e9+7; const int N=2e6+10; const int inf=0x7f7f7f7f; ll gcd(ll a,ll b) { return b==0?a:gcd(b,a%b); } ll lcm(ll a,ll b) { return a*(b/gcd(a,b)); } template <class T> void read(T &x) { char c; bool op = 0; while(c = getchar(), c < '0' || c > '9') if(c == '-') op = 1; x = c - '0'; while(c = getchar(), c >= '0' && c <= '9') x = x * 10 + c - '0'; if(op) x = -x; } template <class T> void write(T x) { if(x < 0) x = -x, putchar('-'); if(x >= 10) write(x / 10); putchar('0' + x % 10); } double s; double dfs(double x,double y,int n) { if(n==1) return max(x,y)/min(x,y); double a=x/n,b=y/n,ans=inf; for(int i=1;i<=n/2;i++) { ans=min(ans,min(max(dfs(i*a,y,i),dfs(x-i*a,y,n-i)),max(dfs(x,i*b,i),dfs(x,y-i*b,n-i)))); } return ans; } int main() { double x,y; int n; scanf("%lf%lf%d",&x,&y,&n); s=dfs(x,y,n); printf("%.6f",s); return 0; }