AC了,但不理解为什么dp数组从左到右累加,却有的值左边会比右边大?

#include<bits/stdc++.h>
using namespace std;
const int N = 110;
const int mod = 1e6+ 7;
int n, m;
int arr[N];
int dp[N][N];
signed main()
{
	cin >> n >> m;
	for (int i = 1; i <= n; i++)
		cin >> arr[i];
	
	dp[0][0] = 1;
	for (int i = 1; i <= n; i++)
		for (int j = 0; j <= m; j++)
			for (int k = 0; k <= arr[i]; k++)
			{
				if (j >= k)
					dp[i][j] =(dp[i][j]+ dp[i-1][j - k] )%mod;
		}
	/*for (int i = 1; i <= n; i++)
	{
		for (int j = 0; j <= m; j++)
			cout << dp[i][j] << ' ';
		cout << endl;
	}*/
	cout << dp[n][m]<<endl;
	return 0;
}