hdu 3652

總算自己套模版套出來一道 雖然是思維 不過代碼比三維的精簡

#include <iostream>
#include <algorithm>
#include <queue>
#include <cstring>
#include <cstdio>
#include <vector>
#include <string>
#include <iterator>
#include <cmath>
#include <deque>
#include <stack>
#include <cctype>
#include <iomanip>
using namespace std;

typedef long long ll;
typedef long double ld;

const int N = 10;
const int INF = 0xfffffff;
const double EPS = 1e-8;
const ll MOD = 1e9 + 7;
const ld PI = acos (-1.0);

#define INFL 0x7fffffffffffffffLL
#define met(a, b) memset(a, b, sizeof(a))
#define put(a) cout << setiosflags(ios::fixed) << setprecision(a)

ll n;
int dp[15][20][10][2], bit[15];

int calc (ll n);
int dfs (int len, int mod, int pre, bool is13, bool ismax);

int main ()
{
    met (dp, -1);
    for (; cin >> n; cout << calc(n) << endl);
    return 0;
}

int calc (ll x)
{
    int len = 0;
    for (;x; bit[len++] = x % 10, x /= 10);
    return dfs (len-1, 0, false, false, true);
}

int dfs (int len, int mod, int pre, bool is13, bool ismax)
{
    if (len == -1) return is13 && ((mod + 13)% 13 == 0);
    if (!ismax && dp[len][mod][pre][is13] != -1) return dp[len][mod][pre][is13];
    ll cnt = 0;
    int maxnum = ismax ? bit[len] : 9;
    for (int i=0; i<=maxnum; i++)
        cnt += dfs(len - 1, (mod * 10 + i) % 13, i, is13 || (pre == 1 && i == 3), ismax && i == maxnum);
    return ismax ? cnt : dp[len][mod][pre][is13] = cnt;
}