爆炸的符卡洋洋洒洒

#include<bits/stdc++.h>
using namespace std;

#define rep(i,l,r) for(int i=(l);i<=(r);i++)
#define per(i,l,r) for(int i=(l);i>=(r);i--)
#define ll long long
#define pii pair<int, int>
#define mset(s,t) memset(s,t,sizeof(t))
#define mcpy(s,t) memcpy(s,t,sizeof(t))
#define fir first
#define pb push_back
#define sec second
#define sortall(x) sort((x).begin(),(x).end())
inline int read () {
	int x = 0, f = 0;
	char ch = getchar();
	while (!isdigit(ch)) f |= (ch=='-'),ch= getchar();
	while (isdigit(ch)) x = x * 10 + ch - '0', ch = getchar();
	return f?-x:x;
}
template<typename T> void print(T x) {
	if (x < 0) putchar('-'), x = -x;
	if (x >= 10) print(x/10);
	putchar(x % 10 + '0');
}
const int N = 2e3 + 10;
ll n, k;
ll a[N], b[N];
ll dp[N];
void solve() {
  cin >> n >> k;
    for (int i = 0; i <= k; i ++) dp[i] = -1e18;
   dp[0] = 0;
    for (int i = 1; i <= n; i ++) {
    	int a ,b;
    	cin >> a >> b;
    	ll ndp[N];
    	mcpy(ndp, dp);
    	for (int j = 0; j < k; j ++) {
    		int news = (j + a) %k;
			ndp[news] = max (ndp[news], dp[j] + b);
		}
		mcpy(dp, ndp);
	}
	ll ans = dp[0];
	if (ans == 0) ans = -1;
	cout << ans << endl;
}
int main () {
    int t;
    t = 1; 
    while (t --) solve();
    return 0;
}

考虑这一题的时候一直在想余数能不能加减 dp[i][j] = max (dp[i][j], dp[i - 1][(j - a[i]%k + k)%k] + k)