2017 Netease Distribute Biscuit

2017.netease.distribute.biscuit.cpp

#include <iostream>
#include <string>
#include <cstdio>
#include <cstring>
#include <vector>
#include <queue>
#include <cmath>
#include <unordered_map>
using namespace std;

#define ff(i, n) for (int i = 0, END = (n); i < END; i ++)
#define fff(i, n, m) for (int i = (n), END = (m); i <= END; i ++)
#define dff(i, n, m) for (int i = (n), END = (m); i >= END; i --)
#define travel(e, first) for (int e = first, v = vv[first]; ~e; e = nxt[e], v = vv[e])
#define clr(a, b) memset(a, b, sizeof(a))
typedef long long ll;


int main() {
    int n;
    string in;

    while (cin >> in >> n) {
        unordered_map<int, ll> store[2];
        int now = 0, pre = 1;
        store[now][0] = 1;

        for (char ch: in) {
            swap(now, pre); store[now].clear();

            ff (j, 10) {
                if (isdigit(ch) && ch - '0' != j) continue;

                for (auto it: store[pre]) {
                    store[now][(it.first * 10 + j) % n] += it.second;
                }
            }
        }

        cout << store[now][0] << endl;
    }
}