Codeforces Round #280 (Div. 2) A. Vanya and Cubes 水题
A. Vanya and Cubes
time limit per test
1 secondmemory limit per test
256 megabytesinput
standard inputoutput
standard outputVanya got n cubes. He decided to build a pyramid from them. Vanya wants to build the pyramid as follows: the top level of the pyramid must consist of 1 cube, the second level must consist of 1 + 2 = 3 cubes, the third level must have 1 + 2 + 3 = 6 cubes, and so on. Thus, the i-th level of the pyramid must have 1 + 2 + ... + (i - 1) + i cubes.
Vanya wants to know what is the maximum height of the pyramid that he can make using the given cubes.
Input
The first line contains integer n (1 ≤ n ≤ 104) — the number of cubes given to Vanya.
Output
Print the maximum possible height of the pyramid in the single line.
Sample test(s)
Input
1
Output
1
Input
25
Output
4
Note
Illustration to the second sample:
#include <cstdio> #include <cmath> #include <cstring> #include <ctime> #include <iostream> #include <algorithm> #include <set> #include <vector> #include <sstream> #include <queue> #include <typeinfo> #include <fstream> typedef long long ll; using namespace std; //freopen("D.in","r",stdin); //freopen("D.out","w",stdout); #define sspeed ios_base::sync_with_stdio(0);cin.tie(0) int main() { int n; cin>>n; int ans=0; int kill=1; int sum=0; while(ans<=n) { sum+=kill; ans+=sum; kill++; } cout<<kill-2<<endl; return 0; }