题目大意:给出一个整数,问吧这个整数分成任意多个正整数只和的最大乘积是多少。
思路:根据小学奥数的基本知识,我们要吧这个数字分成尽量多个3。然后这个题就解决了。
CODE:
#include <cstdio>
#include <cstring>
#include <iostream>
#include <algorithm>
using namespace std;
struct BigInt{
int num[10010],len;
BigInt(int _ = 0) {
memset(num,0,sizeof(num));
num[len = 1] = _;
}
BigInt operator *(int a)const {
BigInt re;
re.len = len;
int temp = 0;
for(int i = 1; i <= len; ++i) {
re.num[i] = num[i] * a + temp;
temp = re.num[i] / 10;
re.num[i] %= 10;
}
while(temp)
re.num[++re.len] = temp % 10,temp /= 10;
return re;
}
};
int n;
int main()
{
cin >> n;
BigInt ans(1);
if(n % 3 == 0)
for(int i = 1; i <= n / 3; ++i)
ans = ans * 3;
else if(n % 3 == 1) {
for(int i = 1; i <= (n - 1) / 3 - 1; ++i)
ans = ans * 3;
ans = ans * 4;
}
else {
for(int i = 1; i <= (n - 1) / 3; ++i)
ans = ans * 3;
ans = ans * 2;
}
cout << ans.len << endl;
for(int i = ans.len,T = 1; T <= min(100,ans.len); ++T,--i)
printf("%d",ans.num[i]);
return 0;
}原文:http://blog.csdn.net/jiangyuze831/article/details/43602591