C :

#include <stdio.h>
#include <string.h>

#define MAXN 1000
#define _clr(x) memset(x,0xff,sizeof(int)*MAXN)

int f[10][10] = { { 2, 1, 7 }, { 0 }, { 0 }, { 2, 1, 7 }, { 1, 1 }, { 0 }, { 1, 5 },
    { 1, 1 }, { 9, 0, 1, 2, 3, 4, 5, 6, 7, 9 }, { 5, 1, 3, 4, 5, 7 }
};
int g[MAXN][MAXN], match[MAXN],mark[MAXN],n;
//邻接矩阵、 
int hungary(int x)
{
	int i;  
    for(i=0;i<n;i++)  
    {  
        if(g[x][i]&&!mark[i])  
        {  
            mark[i]=1;//标记这一点走过了   
            if(match[i]==-1||hungary(match[i]))  
            {  
                match[i]=x;//匹配的真正含义   
                return 1;  
            }  
        }  
    }  
    return 0; 
}

int main()
{
    int i, j, k, a[MAXN];
    while (scanf("%d", &n) != EOF)
    {
        for (i = 0; i < n; i++)
            scanf("%d", &a[i]);
        memset(g, 0, sizeof(g));
        for (i = 0; i < n; i++)
        {
            if (a[i] == 1 || a[i] == 2 || a[i] == 5)
                continue;//剪了个枝 
            for (j = i + 1; j < n; j++)
            {
                if (a[i] == a[j])
                    continue;
                for (k = 1; k <= f[a[i]][0]; k++)
                    if (a[j] == f[a[i]][k])
                    {
                        g[i][j] = 1;
                        break;
                    }
            }
        }//整个这个循环就是初始化邻接矩阵、f数组也只在这里用一次 
        int sum=0;
        memset(match,-1,sizeof(match));
        for(i=0;i<n;i++)
        {
        	memset(mark,0,sizeof(mark));
        	sum+=hungary(i);
        }
        printf("%d\n", n - sum);
    }
    return 0;
}

C++ :

#include <stdio.h>
#include <string.h>

#define MAXN 1000
#define _clr(x) memset(x,0xff,sizeof(int)*MAXN)

int f[10][10] = { { 2, 1, 7 }, { 0 }, { 0 }, { 2, 1, 7 }, { 1, 1 }, { 0 }, { 1, 5 },
				{ 1, 1 }, { 9, 0, 1, 2, 3, 4, 5, 6, 7, 9 }, { 5, 1, 3, 4, 5, 7 } };
int g[MAXN][MAXN], match1[MAXN], match2[MAXN];

int hungary(int m, int n, int mat[][MAXN], int *match1, int *match2) {
	int s[MAXN], t[MAXN], p, q, ret = 0, i, j, k;
	for (_clr(match1),_clr(match2), i = 0; i < m; ret += (match1[i++] >= 0))
		for (_clr(t),s[p = q = 0] = i; p <= q && match1[i] < 0; p++)
			for (k = s[p], j = 0; j < n && match1[i] < 0; j++)
				if (mat[k][j] && t[j] < 0) {
					s[++q] = match2[j];
					t[j] = k;
					if (s[q] < 0)
						for (p = j; p >= 0; j = p) {
							match2[j] = k = t[j];
							p = match1[k];
							match1[k] = j;
						}
				}
	return ret;
}

int main() {
	int n, i, j, k, a[MAXN];
	while (scanf("%d", &n) != EOF) {
		for (i = 0; i < n; i++)
			scanf("%d", &a[i]);
		memset(g, 0, sizeof(g));
		for (i = 0; i < n; i++) {
			if (a[i] == 1 || a[i] == 2 || a[i] == 5)
				continue;
			for (j = i + 1; j < n; j++) {
				if (a[i] == a[j])
					continue;
				for (k = 1; k <= f[a[i]][0]; k++)
					if (a[j] == f[a[i]][k]) {
						g[i][j] = 1;
						break;
					}
			}
		}
		printf("%d\n", n - hungary(n, n, g, match1, match2));
	}
	return 0;
}