2018京东笔试 疯狂序列 神奇数

疯狂序列

#include <iostream>
#include <math.h>
using namespace std;
int main()
{

long long n;
long long m, a, b, res;
while (scanf("%lld", &n) != EOF)
{
m = sqrt((double)2 * n);
a = m*(m + 1) / 2;
b = (m + 1)*(m + 2) / 2;
if (n <= a)
res = m;
else if (n <= b)
res = m + 1;
else
res = m + 2;
printf("%lld\n", res);
}
return 0;

}

神奇数

#include <iostream>
#include <math.h>
#include <vector>
#include <algorithm>
#include <numeric>
#include <map>

using namespace::std;

bool coreCode2(vector<int>& vec)
{
int len = vec.size();

int sum = accumulate(vec.begin(), vec.end(), 0);
vector<vector<int>> dp(len + 1, vector<int>(sum / 2 + 1));

for (int i = 1; i <= len; ++i) {
for (int j = 1; j <= sum / 2; ++j) {
if (j >= vec[i - 1])
dp[i][j] = max(dp[i - 1][j], dp[i - 1][j - vec[i - 1]] + vec[i - 1]);
else
dp[i][j] = dp[i - 1][j];
}
}
if ((sum - 2 * dp[len][sum / 2]) == 0)
{
return true;
}
else
{
return false;
}
}

int main()
{
int left = 0, right = 0;
cin >> left >> right;

int result(0);
bool flag;
map<vector<int>, bool> record;

for (auto i = left; i <= right; ++i)
{
vector<int> numVec;
numVec.reserve(10);
int tmp;
int num1 = i;
while (num1)
{
tmp = num1 % 10;
num1 = num1 / 10;
numVec.push_back(tmp);
}
sort(numVec.begin(), numVec.end());

auto iter = record.find(numVec);

if (iter == record.end())
{
flag = coreCode2(numVec);
record[numVec] = flag;
if (flag)
{
++result;
}
}
else
{
flag = iter->second;
if (flag)
{
++result;
}
}
}

cout << result;

return 0;
}