Educational Codeforces Round 50 (Rated for Div. 2)的A、B、C三题AC代码

A题链接：https://codeforces.com/contest/1036/problem/A

A题AC代码：

 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
 #include <math.h>
 #include <malloc.h>
 #include <stdbool.h>
 #include <ctype.h>

 typedef long long ll;

 int main()
 {
     ll n, k, i, j, ans;
     while( ~scanf( "%I64d%I64d", &n, &k ) )
     {
         printf( "%I64d\n", ( k + n -  ) / n );
     }
     return ;
 }

B题链接：https://codeforces.com/contest/1036/problem/B

B题AC代码：

 #include <iostream>
 #include <cstring>
 #include <cstdio>

 typedef unsigned long long ULL;
 typedef const int cint;
 typedef long long LL;
 using namespace std;

 int q;
 LL n,m,k;
 template< typename Q >
 void inin(Q &);

 int main()
 {
     inin(q);
     while( q -- )
     {
         inin(n);
         inin(m);
         inin(k);
         if( n > m )
             swap( n, m );
         if( k < m )
             printf( "-1" );
         else
         {
             if( n == m )
             {
                 if( ( k-n ) &  )
                     printf( "%I64d", k -  );
                 else
                     printf( "%I64d", k );
             }
             else
             {
                 LL temp = m - n;
                 if( temp &  )
                     printf( "%I64d", k -  );
                 else
                 {
                     if( ( k - m ) &  )
                         printf( "%I64d", k -  );
                     else
                         printf( "%I64d", k );
                 }
             }
         }
         printf( "\n" );
     }
     return ;
 }

 template< typename Q >
 void inin( Q &x )
 {
     x=;
     int f=;
     char ch;
     scanf( "%c", &ch );
     while( ch < '' || ch > '' )
     {
         if( ch == '-' )
             f = ;
         scanf( "%c", &ch );
     }
     while( ch >= '' && ch <= '' )
     {
         x = x* + ch - '';
         scanf( "%c", &ch );
     }
     x = f?-x:x;
 }

C题链接：https://codeforces.com/contest/1036/problem/C

C题AC代码：

 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
 #include <math.h>
 #include <malloc.h>
 #include <stdbool.h>
 #include <ctype.h>

 typedef long long ll;

 ll Arr[][];
 int dig[];
 ll dp( int, int, int );
 ll calc(ll);

 int main()
 {
     memset( Arr, -, sizeof(Arr) );
     int i, T=;
     ll L,R;
     while( ~scanf( "%d", &T ) )
     {
         for ( i = ; i <= T; i ++ )
         {
             scanf( "%I64d%I64d", &L, &R );
             L--;
             printf( "%I64d\n", calc(R) - calc(L) );
         }
     }
     return ;
 }

 ll dp( int len, int res, int lim )
 {
     if ( res >  )
         return ;
     if ( len ==  )
         return ;
     if ( !lim && Arr[len][res] >  )
         return Arr[len][res];
     ll ret = ;
     int up = ;
     if (lim)
         up=dig[len];
     int i;
     for ( i = ; i <= up; i ++ )
         ret += dp( len-, res+(i>), lim && ( i == up ) );
     if (!lim) Arr[len][res]=ret;
     return ret;
 }

 ll calc(ll x)
 {
     int _sum = ;
     while (x)
     {
         dig[ ++ _sum ] = x % ;
         x /= ;
     }
     return dp( _sum, ,  );
 }

全部测过样例再提交，另外，本蒟蒻还从未做过D……