题意:对于任意一个数 N ,寻找在 100,0000 之内按照规则( N 为奇数 N = N * 3 + 1 ,N 为偶数 N = N / 2 ,直到 N = 1 时的步数 )步数的最大值 思路:记忆化搜索即可,利用之前搜索的值加速搜索,如果当前搜索值在之前已经处理过,那么直接利用当前搜索值 + 到当前数的步数即为该数的步数 /************************************************************************* > File Name…

记忆化搜索来一发.没想到中间会爆int #include <bits/stdc++.h> using namespace std; const int MAXN = 1000000; int dp[MAXN]; int dfs(long long num) { if(num <= MAXN && dp[num]) return dp[num]; if(num == 1) return (dp[num] = 1); if(num&1) { if(num <=…

The following iterative sequence is defined for the set of positive integers: n n/2 (n is even) n 3n + 1 (n is odd) Using the rule above and starting with 13, we generate the following sequence: 13 40 20 10 5 16 8 4 2 1 It can be seen that this seque…

def collatz(num,i): i =i + 1 if num%2 == 0: return collatz(num//2,i) elif num == 1: return i else: return collatz((num+(num<<1) + 1),i) k = 0 j = 0 for i in range(666666,1000000): temp = collatz(i,0) if k < temp: j,k = i,temp print(j,k) print(j,k…

本题来自 Project Euler 第14题:https://projecteuler.net/problem=14 ''' Project Euler: Problem 14: Longest Collatz sequence The following iterative sequence is defined for the set of positive integers: n → n/2 (n is even) n → 3n + 1 (n is odd) Using the rule…

本题来自 Project Euler 第12题:https://projecteuler.net/problem=12 # Project Euler: Problem 12: Highly divisible triangular number # The sequence of triangle numbers is generated by adding the natural numbers. # So the 7th triangle number would be 1 + 2 + 3…

In Problem 42 we dealt with triangular problems, in Problem 44 of Project Euler we deal with pentagonal number, I can only wonder if we have to deal with septagonal numbers in Problem 46. Anyway the problem reads Pentagonal numbers are generated by t…

本题来自 Project Euler 第22题:https://projecteuler.net/problem=22 ''' Project Euler: Problem 22: Names scores Using names.txt (right click and 'Save Link/Target As...'), a 46K text file containing over five-thousand first names, begin by sorting it into al…

本题来自 Project Euler 第11题:https://projecteuler.net/problem=11 # Project Euler: Problem 10: Largest product in a grid # In the 20×20 grid below, four numbers along a diagonal line have been marked in red. # The product of these numbers is 26 × 63 × 78 ×…

本题来自 Project Euler 第2题:https://projecteuler.net/problem=2 # Each new term in the Fibonacci sequence is generated # by adding the previous two terms. # By starting with 1 and 2, the first 10 terms will be: # 1, 2, 3, 5, 8, 13, 21, 34, 55, 89, ... # By…