【HDOJ】5179 beautiful number

DFS。

 /* 5179 */
 #include <iostream>
 #include <algorithm>
 #include <map>
 #include <cstdio>
 #include <cstring>
 using namespace std;

 #define MAXN 1500

 map<int, bool> tb;
 int a[MAXN], n, v;
 int buf[][] = {
     {,},
     {,,,}, {,,,,},
     {,,,}, {,,,},
     {,,},
     {,,}
 };

 void dfs(int beg, int len, int val) {
     int i, k, tmp = *val;
     if (len >= )
         return ;
     for (i=beg; i<=buf[v][]; ++i) {
         k = tmp + buf[v][i];
         if (!tb[k]) {
             tb[k] = true;
             a[n++] = k;
         }
         dfs(i, len+, k);
     }
 }

 void init() {
     int i, j, k;

     n = ;
     for (v=; v<; ++v)
         dfs(, , );
     sort(a, a+n);
 }

 int main() {
     int t, l, r;
     int i, j, k;
     int ans;

     #ifndef ONLINE_JUDGE
         freopen("data.in", "r", stdin);
         freopen("data.out", "w", stdout);
     #endif

     init();
     scanf("%d", &t);
     while (t--) {
         scanf("%d %d", &l, &r);
         ans = ;
         for (i=; i<n; ++i)
             if (l<=a[i] && r>=a[i])
                 ++ans;
         printf("%d\n", ans);
     }

     return ;
 }