简单的DP。
CO
/*
PROGRAM: $PROGRAM
AUTHOR: Su Jiao
DATE: 2010-4-8
DESCRIPTION:
$DESCRIPTION
*/
#include <iostream>
using std::cin;
using std::cout;
#include <fstream>
using std::ifstream;
using std::ofstream;
#include <sstream>
using std::stringstream;
using std::endl;
#include <vector>
using std::vector;
#include <string>
using std::string;
#include <stack>
using std::stack;
#include <queue>
using std::queue;
using std::priority_queue;
#include <set>
using std::set;
#include <map>
using std::map;
using std::pair;
using std::make_pair;
#include <algorithm>
using std::sort;
#include <cassert>
//using std::assert;
class Application
{
int N;
public:
Application()
{
cin>>N;
}
int run()
{
vector<int> f(N+1,N);
f[0]=0;
for (int i=1;i<=N;i++)
{
for (int j=1;j*j<=i;j++)
if (f[i-j*j]+1<f[i]) f[i]=f[i-j*j]+1;
}
cout<<f[N]<<endl;
return 0;
}
};
int main()
{
Application app;
return app.run();
}