1798F - Gifts from Grandfather Ahmed - CodeForces Solution

// Problem: F. Gifts from Grandfather Ahmed
// Contest: Codeforces - Codeforces Round 860 (Div. 2)
// URL: https://codeforces.com/contest/1798/problem/F
// Memory Limit: 256 MB
// Time Limit: 1000 ms

#include<bits/stdc++.h>

using namespace std;
#define MP make_pair
#define debug(x) cerr<<#x<<" = "<<x<<" ";
#define debug_(x) cerr<<#x<<" = "<<x<<"\n";
typedef long long ll;
typedef unsigned long long ull;
typedef double db;

constexpr int P = 998244353;
int norm(int x) {
    if (x < 0) {
        x += P;
    }
    if (x >= P) {
        x -= P;
    }
    return x;
}
template<class T>
T power(T a, ll b) {
    T res = 1;
    for (; b; b /= 2, a *= a) {
        if (b % 2) {
            res *= a;
        }
    }
    return res;
}
struct Z {
    int x;
    Z(int x = 0) : x(norm(x)) {}
    int val() const {
        return x;
    }
    Z operator-() const {
        return Z(norm(P - x));
    }
    Z inv() const {
        // assert(x != 0);
        return power(*this, P - 2);
    }
    Z &operator*=(const Z &rhs) {
        x = ll(x) * rhs.x % P;
        return *this;
    }
    Z &operator+=(const Z &rhs) {
        x = norm(x + rhs.x);
        return *this;
    }
    Z &operator-=(const Z &rhs) {
        x = norm(x - rhs.x);
        return *this;
    }
    Z &operator/=(const Z &rhs) {
        return *this *= rhs.inv();
    }
    friend Z operator*(const Z &lhs, const Z &rhs) {
        Z res = lhs;
        res *= rhs;
        return res;
    }
    friend Z operator+(const Z &lhs, const Z &rhs) {
        Z res = lhs;
        res += rhs;
        return res;
    }
    friend Z operator-(const Z &lhs, const Z &rhs) {
        Z res = lhs;
        res -= rhs;
        return res;
    }
    friend Z operator/(const Z &lhs, const Z &rhs) {
        Z res = lhs;
        res /= rhs;
        return res;
    }
};
void solve(){
	int n, K;
	cin >> n >> K;
	vector<int>arr(n);
	for(auto &x : arr)cin >> x;
	vector<int>s(K);
	int mxid = 0;
	for(int i = 0; i < K; ++i){
		cin >> s[i];
		if(s[i] > s[mxid])mxid = i;
	}
	vector<bool>use(n, false);
	vector<vector<int>>ans(K);
	auto divbox = [&](int id){
		int len = s[id];
		// cerr << id << " " << len << "\n";
		vector<vector<int>>f(len, vector<int>(len, -1));
		for(int i = 0; i < n; ++i)if(!use[i]){
			for(int j = len - 2; ~j; --j){
				for(int k = 0; k < len; ++k)if(~f[j][k]){
					if(!~f[j + 1][(k + arr[i]) % len]){
						f[j + 1][(k + arr[i]) % len] = i;
					}
				}
			}
			if(!~f[0][arr[i] % len])f[0][arr[i] % len] = i;
		}
		for(int i = len - 1, v = 0; ~i; --i){
			int u = f[i][v];
			use[u] = true;
			ans[id].push_back(arr[u]);
			(v -= arr[u]) %= len;
			if(v < 0)v += len;
		}
	};
	for(int i = 0; i < K; ++i)if(i != mxid)divbox(i);
	int sum = 0;
	for(int i = 0; i < n; ++i){
		if(!use[i]){
			ans[mxid].push_back(arr[i]);
			(sum += arr[i]) %= s[mxid];
		}
	}
	cout << s[mxid] - sum << "\n";
	ans[mxid].push_back(s[mxid] - sum);
	for(int i = 0; i < K; ++i){
		sum = 0;
		for(int j = 0 ; j < (int)ans[i].size(); ++j){
			sum += ans[i][j];
			cout << ans[i][j] << " \n"[j == (int)ans[i].size() - 1];
		}
		assert(sum % s[i] == 0);
	}
}
int main(){
	ios::sync_with_stdio(false);
    cin.tie(nullptr);
    cout.tie(nullptr);
	solve();
	return 0;
}