POJ 3232 Accelerator

二分

 1 #include <cstdio>

 2 #include <cstring>

 3 #include <cstdlib>

 4 #include <algorithm>

 5 

 6 #define LL long long int

 7 

 8 using namespace std;

 9 

10 const int MAXN = 100010;

11 

12 LL a[MAXN];

13 LL M, K;

14 int N;

15 

16 bool check( LL mid )

17 {

18     LL TotUse = mid * M;

19     LL use = 0;

20     for ( int i = 0; i < N; ++i )

21     {

22         if ( a[i] <= mid ) continue;

23         if ( mid * K < a[i] ) return false;

24 

25         LL tp = ( a[i] - mid ) / ( K - 1 );

26         if ( ( a[i] - mid ) % ( K - 1 ) ) ++tp;

27         use += tp;

28     }

29     return use <= TotUse;

30 }

31 

32 int main()

33 {

34     int T;

35    // freopen( "s.out", "w", stdout );

36     scanf( "%d", &T );

37     while ( T-- )

38     {

39         LL high = -1;

40         scanf( "%d", &N );

41         for ( int i = 0; i < N; ++i )

42         {

43             scanf( "%I64d", &a[i] );

44             high = max( high, a[i] );

45         }

46         scanf( "%I64d%I64d", &M, &K );

47         if ( K == 1 )

48         {

49             printf( "%I64d\n", high );

50             continue;

51         }

52 

53         LL l = 1, r = high;

54         LL mid;

55         while ( l < r )

56         {

57             mid = ( l + r ) >> 1;

58             if ( check( mid ) )

59             {

60                 r = mid;

61             }

62             else l = mid + 1;

63         }

64         printf( "%I64d\n", l );

65     }

66     return 0;

67 }