rt，用 dfs 实现的状压 dp，WA #6、#8、#9，都是比较大的数据点，小数据点基本都没问题。看不出来哪儿错了。

#include <cstdio>
#include <cstring>
#include <algorithm>
using namespace std;
int f[105][50000][7], town[10], n, m;
char str[105];
int _merge(int pos) {
    int ans = 0;
    while (town[pos]) {
        int l = pos, r = pos;
        while (town[l] == town[l - 1] && l > 1)
            l--;
        while (town[r] == town[r + 1] && r < n)
            r++;
        if (l == r)
            break;
        ans += (r - l + 1) << town[pos];
        for (int i = l; i <= r; i++)
            if (i != pos)
                town[i] = 0;
        town[pos] = (town[pos] + 1) % 6;
    }
    return ans;
}
void make_town(int status) {
    for (int i = 1; i <= n; i++) {
        town[i] = status % 6;
        status /= 6;
    }
}
int make_status() {
    int status = 0;
    for (int i = n; i >= 1; i--)
        status = status * 6 + town[i];
    return status;
}
bool full() {
    for (int i = 1; i <= n; i++)
        if (!town[i])
            return false;
    return true;
}
int dfs(int status, int day, int wale) {
    if (day == m + 1)
        return 0;
    int& dp = f[day][status][wale];
    if (dp != -1)
        return dp;
    make_town(status);
    if (full())
        return 0;
    if (wale) {
        for (int i = 1; i <= n; i++)
            if (!town[i]) {
                town[i] = wale;
                dp = max(dp, _merge(i) + dfs(make_status(), day, 0));
                make_town(status);
            }
    } else
        dp = max(dp, dfs(status, day + 1, str[day] - '0'));
    for (int i = 1;  i <= n; i++)
        if (!town[i]) {
            town[i] = str[day] - '0';
            dp = max(dp, _merge(i) + dfs(make_status(), day + 1, wale));
            make_town(status);
        }
    return dp;
}
int main() {
    memset(f, -1, sizeof(f));
    scanf("%d%d%s", &n, &m, str + 1);
    printf("%d\n", dfs(0, 1, 0));
    return 0;
}