ZROI#997

川长思鸟来 2023-06-02 11:59 140阅读 0赞

[ZROI\#997][ZROI_997]  
这是某场\\(CF(Div.3)\\)的\\(C\\)题.我当时是选择了现场码.  
因为那场\\(CF\\)我没打.这个题我当时第一眼就觉得有循环节.  
于是就直接考虑循环节,发现它是对的.于是就只需要处理一下细节就好.  
\\(Code:\\)

#include <algorithm> #include <iostream> #include <cstdlib> #include <cstring> #include <cstdio> #include <string> #include <vector> #include <queue> #include <cmath> #include <ctime> #include <map> #include <set> #define MEM(x,y) memset ( x , y , sizeof ( x ) ) #define rep(i,a,b) for (int i = a ; i <= b ; ++ i) #define per(i,a,b) for (int i = a ; i >= b ; -- i) #define pii pair < int , int > #define X first #define Y second #define rint read<int> #define int long long #define pb push_back using std::set ; using std::pair ; using std::max ; using std::min ; using std::priority_queue ; using std::vector ; using std::swap ; using std::sort ; using std::unique ; using std::greater ; template < class T > inline T read () { T x = 0 , f = 1 ; char ch = getchar () ; while ( ch < '0' || ch > '9' ) { if ( ch == '-' ) f = - 1 ; ch = getchar () ; } while ( ch >= '0' && ch <= '9' ) { x = ( x << 3 ) + ( x << 1 ) + ( ch - 48 ) ; ch = getchar () ; } return f * x ; } const int N = 100 ; bool mk[15] ; int n , m , T , tot ; vector < int > tmp ; signed main (int argc , char * argv[]) { T = rint () ; while ( T -- ) { n = rint () ; m = rint () ; tot = 0 ; int sum = 0 ; if ( m > n ) { puts ("0") ; continue ; } if ( n == m ) { printf ("%lld\n" , m % 10 ) ; continue ; } rep ( i , 0 , 10 ) mk[i] = false ; tmp.clear () ; while ( true ) { ++ tot ; int t = m * tot % 10 ; if ( mk[t] ) break ; tmp.pb ( t ) ; sum += t ; mk[t] = true ; } int rpt = ( n / m ) / (int)tmp.size () ; int ans = sum * rpt ; rep ( i , 0 , n / m % (int)tmp.size () - 1 ) ans += tmp[i] ; printf ("%lld\n" , ans ) ; } return 0 ; }

转载于:https://www.cnblogs.com/Equinox-Flower/p/11486593.html

[ZROI_997]: http://www.zhengruioi.com/problem/997