CodeForces 839B - Game of the Rows | Codeforces Round #428 (Div. 2)

血崩- -

/*
CodeForces 839B - Game of the Rows [ 贪心,分类讨论] | Codeforces Round #428 (Div. 2)
注意 
2 7
2 2 2 2 2 2 2
这组- -
*/
#include <bits/stdc++.h>
using namespace std;
int n, n2, n4, a[105], k;
bool solve()
{
    n2 = 2*k;
    n4 = k;
    for (int i = 1; i <= n; i++)
    {
        if (a[i] >= 4 && n4)
        {
            int t = a[i]/4;
            a[i] -= min(t, n4)*4;
            n4 -= min(t, n4);
        }
    }
    for (int i = 1; i <= n; i++)
    {
        if (a[i] >= 2 && n2)
        {
            int t = a[i]/2;
            a[i] -= min(t, n2)*2;
            n2 -= min(t, n2);
        }
    }
    for (int i = 1; i <= n; i++)
    {
        if (a[i] && n2)
        {
            int t = a[i];
            a[i] -= min(t, n2);
            n2 -= min(t, n2);
        }
    }
    int m2 = 0, m1 = 0, m3 = 0;
    for (int i = 1; i <= n; i++)
        if (a[i] == 3) m3++;
        else if (a[i] == 2) m2++;
        else if (a[i] == 1) m1++;
    int sum = m3;
    if (m1 <= m2)
    {
        sum += m1;
        m2 -= m1;
        sum += m2/3*2;
        m2 %= 3;
        sum += m2;
    }
    else
    {
        sum += m2;
        m1 -= m2;
        sum += (m1+1)/2;
    }
    if (sum > n4) return 0;
    return 1;
}
int main()
{
    scanf("%d%d", &k, &n);
    for (int i = 1; i <= n; i++) scanf("%d", &a[i]);
    if (solve()) puts("YES");
    else puts("NO");
}