题目描述
思路：对每一个输入的数字n进行验证，把验证过的数字对应的arr标记为1，然后对这些输入的数字从大到小排序，输出所有arr=0的数字即为关键数字
#include <iostream>
#include <vector>
#include <algorithm>
using namespace std;
int arr[10000];
bool cmp(int a, int b) {return a > b;}
int main() {
int k, n, flag = 0;
cin >> k;
vector<int> v(k);
for (int i = 0; i < k; i++) {
cin >> n;
v[i] = n;
while (n != 1) {
if (n % 2 != 0) n = 3 * n + 1;
n = n / 2;
if (arr[n] == 1) break;
arr[n] = 1;
}
}
sort(v.begin(), v.end(), cmp);
for (int i = 0; i < v.size(); i++) {
if (arr[v[i]] == 0) {
if (flag == 1) cout << " ";
cout << v[i];
flag = 1;
}
}
return 0;
}
def callatz(n):
t = set()
while n != 1 :
t.add(n)
if n % 2 == 0:
n /= 2
else:
n = (n*3+1)/2
return t
input()
l = list(map(int,set(input().split())))
ts = set()
tl = []
for i in l:
ss = callatz(i)
if ts.issubset(ss):
ts = ss
tl = [i]
elif ts.issuperset(ss):
continue
else:
for j in tl:
if callatz(j).issubset(ss):
tl.remove(j)
ts |= ss
tl.append(i)
tl = sorted(tl, reverse=True)
print(' '.join(str(x) for x in tl))
