整数拆分

wiki上看到了一个厉害的递推式

#include <iostream>
using namespace std;

int main() {
    const int len = 121;
    int num[len + 1] = { 1 };

    for (int i = 1; i <= len; ++i)
        for (int j = i; j <= len; ++j)
            num[j] += num[j - i];

    for (int i = 0; i <= len; i++)
        cout << i << ' ' << num[i] << endl;
    return 0;
}