Create 3652_kg20006.cpp

From http://acm.hdu.edu.cn/discuss/problem/post/reply.php?postid=27200&messageid=1&deep=0

HDOJ/3652_kg20006.cpp

@@ -0,0 +1,35 @@
+#include<bits/stdc++.h>
+#define ll long long int
+using namespace std;
+ll num[30];
+ll dp[30][15][5];
+ll dfs(int pos, int mod, int st, bool f){
+    if(pos < 1) return st == 2 && mod == 0;
+    if(!f && dp[pos][mod][st] != -1) return dp[pos][mod][st];
+    int end = f? num[pos] : 9;
+    ll res = 0;
+    for(int i = 0; i <= end; ++i){
+        int nmod = (mod*10 + i) %13;
+        bool nf = (f && i == end);
+        if(st == 2 || (st == 1 && i == 3)) res += dfs(pos-1, nmod, 2, nf);
+        else if(i == 1) res += dfs(pos-1, nmod, 1, nf);
+        else res += dfs(pos-1, nmod, 0, nf);
+    }
+    if(!f) dp[pos][mod][st] = res;
+    return res;
+}
+ll solve(ll n){
+    int len = 0;
+    while(n){
+        num[++len] = n%10;
+        n /= 10;
+    }
+    return dfs(len, 0, 0, 1);
+}
+int main(){
+    ll n;
+    while(scanf("%lld", &n) != EOF){
+        memset(dp, -1, sizeof(dp));
+        printf("%lld\n", solve(n));
+    }
+}