hdu4282 A very hard mathematic problem(二分)
阿新 • • 發佈:2019-02-14
題意:
給你一個
題解:
我們去列舉X,Z然後二分Y就可以了,因為X的最大為24000,Z最大為31。
程式碼:
#include<cstdio>
#include<cstring>
#include<iostream>
#include<sstream>
#include<algorithm>
#include<vector>
#include<bitset>
#include<set>
#include<queue>
#include<stack>
#include<map>
#include<cstdlib>
#include<cmath>
#define PI 2*asin(1.0)
#define LL long long
#define pb push_back
#define pa pair<int,int>
#define clr(a,b) memset(a,b,sizeof(a))
#define lson lr<<1,l,mid
#define rson lr<<1|1,mid+1,r
#define bug(x) printf("%d++++++++++++++++++++%d\n",x,x)
#define key_value ch[ch[root][1]][0]
const int MOD = 1000000007;
const int N = 30000 + 100;
const int maxn = 100+ 14;
const int letter = 130;
const int INF = 1e9;
const double pi=acos(-1.0);
const double eps=1e-8;
using namespace std;
inline int read()
{
int x=0,f=1;char ch=getchar();
while(ch<'0'||ch>'9'){if(ch=='-')f=-1;ch=getchar();}
while(ch>='0'&&ch<='9'){x=x*10+ch-'0';ch=getchar();}
return x*f;
}
LL n;
LL dp[N][32];
int main(){
for(int i=1;i<N;i++) dp[i][0]=1ll;
for(int i=1;i<=N;i++){
for(int j=1;j<31;j++) {
if(dp[i][j-1]*1ll*i>(1ll<<31)) break;
dp[i][j]=dp[i][j-1]*i;
}
}
while(~scanf("%I64d",&n)&&n){
int ans=0;
for(LL i=1;i<=30000;i++){
for(LL j=2;j<=31;j++){
if(!dp[i][j]) break;
LL l=i+1ll,r=30000;
while(l<=r){
LL mid=(l+r)/2ll;
if(!dp[mid][j]) {r=mid-1;continue;}
LL sum=dp[i][j]+dp[mid][j]+i*j*mid;
if(sum==n) {ans++;break;}
else if(sum<n) l=mid+1ll;
else r=mid-1ll;
}
}
}
printf("%d\n",ans);
}
return 0;
}