python/TangDou/AcWing/JiShuDP/900_1.cpp

#include <bits/stdc++.h>

using namespace std;

const int N = 1010;
const int MOD = 1e9 + 7;
int f[N];
int n;

int main() {
    cin >> n;
    f[0] = 1; // 容量为0时，前 i 个物品全不选也是一种方案
    for (int i = 1; i <= n; i++)
        for (int j = i; j <= n; j++) // 完全背包从小到大
            f[j] = (f[j] + f[j - i]) % MOD;
    cout << f[n] << endl;
    return 0;
}