Codeforces Round #367 (Div. 2)

A题　　Beru-taxi

随便搞搞。。

 #include <cstdio>
 #include <cmath>
 using namespace std;
 int a,b,n;
 struct _
 {
     int x,y,v;
 }p[];
 double dis2(_ A)
 {
     return (a - A.x) * (a - A.x) + (b - A.y) * (b - A.y);
 }
 int main()
 {
     scanf("%d%d%d", &a, &b, &n);
     ; i < n; i++)
         scanf("%d%d%d", &p[i].x, &p[i].y, &p[i].v);
     double ans = 1.0 * 0x3f3f3f3f;
     ; i < n; i++)
     {
         double temp = (double) sqrt(dis2(p[i])) / p[i].v;
         )
             ans = temp;
     }
     printf("%lf\n",ans);
     ;
 }

B题　　Interesting drink

就是找有几个不大于它的数嘛。sort一下，upperbound就行。

 #include <cstdio>
 #include <algorithm>
 using namespace std;
  + ];
 int main()
 {
     int n,q,x;
     scanf("%d", &n);
     ; i < n; i++)
         scanf("%d", &a[i]);
     scanf("%d", &q);
     sort(a,a+n);
     ; i < q; i++)
     {
         scanf("%d", &x);
         int pos = upper_bound(a,a+n,x) - a;
         printf("%d\n",pos);
     }
     ;
 }

C题　　Hard problem

dp，加一个维度来表示，是否翻转过！！！

其次，WA了一次是因为这个判断的时候，不等号是要带等号的。>= <= 而不是> < ;

 #include <cstdio>
 #include <cstring>
 #include <algorithm>
 #include <iostream>
 using namespace std;
 typedef long long LL;
  + ;
 const LL INF = 1e17;
 int c[maxn];
 LL dp[maxn][];
 string s[maxn];
 int main()
 {
     int n;
     cin>>n;
     ; i < n; i++)
         cin>>c[i];
     ; i < n; i++)
         cin>>s[i];
     //init
     ; i < n; i++)
     {
         dp[i][] = INF;
         dp[i][] = INF;
     }
     dp[][] = ;
     dp[][] = c[];
     string s10,s11,s20,s21;
     ; i < n; i++)
     {
         s10 = s11 = s[i-];
         reverse(s11.begin(),s11.end());

         s20 = s21 = s[i];
         reverse(s21.begin(),s21.end());

         if(s10 <= s20)
             dp[i][] = min(dp[i][], dp[i-][]);
         if(s11 <= s20)
             dp[i][] = min(dp[i][], dp[i-][]);
         if(s10 <= s21)
             dp[i][] = min(dp[i][], dp[i-][] + (LL)c[i]);
         if(s11 <= s21)
             dp[i][] = min(dp[i][], dp[i-][] + (LL)c[i]);
     }
     LL ans = min(dp[n-][], dp[n-][]);
     cout<<(ans == INF ? - : ans)<<endl;

     ;
 }

D题　　Vasiliy's Multiset

据说是裸的字典树orz。

01字典树

 #include <set>
 #include <queue>
 #include <cmath>
 #include <cstdio>
 #include <vector>
 #include <cstring>
 #include <algorithm>
 using namespace std;
 typedef long long LL;
 #define mem(x,y) memset(x, y, sizeof(x))
 #define lson l,m,rt << 1
 #define rson m+1,r,rt << 1 | 1

 const int INF = 0x3f3f3f3f;
 ;
 int n;

 ;//种类数目调节
 struct node
 {
     node *next[trie_size];
     int cnt;
     node()
     {
         ; i < trie_size; i++)
             next[i] = NULL;
         cnt = ;
     }
 };

 node *p, *root = new node();

 void trie_insert(int x)
 {
     p = root;
     ; i >= ; i--)
     {
          << i) ?  : ;
         if(p->next[num] == NULL)
             p->next[num] = new node();
         p = p->next[num];
         p->cnt++;
     }
 }

 void trie_delete(int x)
 {
     p = root;
     ;i >= ; i--){
          << i) ?  : ;
         p = p -> next[num];
         p->cnt--;
     }
 }

 int trie_query(int x)
 {
     ;
     p = root;
     ; i >= ; i--)
     {
          << i) ?  : ;
         node *temp;
         temp = p->next[num];
         )
         {
             res +=  << i;
             p = temp;
         }
         else
         {
             p = p->next[!num];
         }
     }
     return res;
 }

 int main()
 {
     trie_insert();

     scanf("%d", &n);
     ; i < n; i++)
     {
         char ch;
         int x;
         getchar();
         scanf("%c%d", &ch, &x);
         if(ch == '+')
         {
             trie_insert(x);
         }
         else if(ch == '-')
         {
             trie_delete(x);
         }
         else if(ch == '?')
         {
             int ans = trie_query(x);
             printf("%d\n", ans);
         }
     }
     ;
 }

E题　　Working routine