Ignatius and the Princess III HDU - 1028

题目传送门:https://vjudge.net/problem/HDU-1028

思路:整数拆分构造母函数的模板题

Ignatius and the Princess III HDU - 1028Ignatius and the Princess III HDU - 1028
  1 //#include<bits/stdc++.h>
2 #include<time.h>
3 #include <set>
4 #include <map>
5 #include <stack>
6 #include <cmath>
7 #include <queue>
8 #include <cstdio>
9 #include <string>
10 #include <vector>
11 #include <cstring>
12 #include <utility>
13 #include <cstring>
14 #include <iostream>
15 #include <algorithm>
16 #include <list>
17 using namespace std;
18 #define eps 1e-10
19 #define PI acos(-1.0)
20 #define lowbit(x) ((x)&(-x))
21 #define zero(x) (((x)>0?(x):-(x))<eps)
22 #define mem(s,n) memset(s,n,sizeof s);
23 #define ios {ios::sync_with_stdio(false);cin.tie(0);cout.tie(0);}
24 typedef long long ll;
25 typedef unsigned long long ull;
26 const int maxn=1e3+5;
27 const int Inf=0x7f7f7f7f;
28 const ll Mod=999911659;
29 const int N=3e3+5;
30 bool isPowerOfTwo(int n) { return n > 0 && (n & (n - 1)) == 0; }//判断一个数是不是 2 的正整数次幂
31 int modPowerOfTwo(int x, int mod) { return x & (mod - 1); }//对 2 的非负整数次幂取模
32 int getBit(int a, int b) { return (a >> b) & 1; }// 获取 a 的第 b 位,最低位编号为 0
33 int Max(int a, int b) { return b & ((a - b) >> 31) | a & (~(a - b) >> 31); }// 如果 a>=b,(a-b)>>31 为 0,否则为 -1
34 int Min(int a, int b) { return a & ((a - b) >> 31) | b & (~(a - b) >> 31); }
35 ll gcd(ll a, ll b) {return b ? gcd(b, a % b) : a;}
36 ll lcm(ll a, ll b) {return a / gcd(a, b) * b;}
37 int Abs(int n) {
38 return (n ^ (n >> 31)) - (n >> 31);
39 /* n>>31 取得 n 的符号,若 n 为正数,n>>31 等于 0,若 n 为负数,n>>31 等于 -1
40 若 n 为正数 n^0=n, 数不变,若 n 为负数有 n^(-1)
41 需要计算 n 和 -1 的补码,然后进行异或运算,
42 结果 n 变号并且为 n 的绝对值减 1,再减去 -1 就是绝对值 */
43 }
44 ll binpow(ll a, ll b,ll c) {
45 ll res = 1;
46 while (b > 0) {
47 if (b & 1) res = res * a%c;
48 a = a * a%c;
49 b >>= 1;
50 }
51 return res%c;
52 }
53 void extend_gcd(ll a,ll b,ll &x,ll &y)
54 {
55 if(b==0) {
56 x=1,y=0;
57 return;
58 }
59 extend_gcd(b,a%b,x,y);
60 ll tmp=x;
61 x=y;
62 y=tmp-(a/b)*y;
63 }
64 ll mod_inverse(ll a,ll m)
65 {
66 ll x,y;
67 extend_gcd(a,m,x,y);
68 return (m+x%m)%m;
69 }
70 ll eulor(ll x)
71 {
72 ll cnt=x;
73 ll ma=sqrt(x);
74 for(int i=2;i<=ma;i++)
75 {
76 if(x%i==0) cnt=cnt/i*(i-1);
77 while(x%i==0) x/=i;
78 }
79 if(x>1) cnt=cnt/x*(x-1);
80 return cnt;
81 }
82 int c1[maxn],c2[maxn];
83 int val[maxn];
84 int main()
85 {
86 ios
87 int n;
88 while(cin>>n)
89 {
90 for(int i=1;i<=n;i++) val[i]=i;
91 mem(c1,0);
92 mem(c2,0);
93 for(int i=0;i<=n;i++) c1[i]=1;
94 for(int i=2;i<=n;i++)
95 {
96 for(int j=0;j<=n;j++)
97 {
98 for(int k=0;k+j<=n;k+=val[i])
99 {
100 c2[j+k]+=c1[j];
101 }
102 }
103 for(int j=0;j<=n;j++)
104 {
105 c1[j]=c2[j];
106 c2[j]=0;
107 }
108 }
109 cout<<c1[n]<<endl;
110 }
111 return 0;
112 }

母函数详解:https://blog.csdn.net/baidu_23955875/article/details/42174965

上一篇:动态规划:HDU-1398-Square Coins(母函数模板)


下一篇:母函数(Generation Function) 入门 + 模板