【题解】Luogu P1582 倒水 二进制

 1 #include<bits/stdc++.h>
 2 using namespace std;
 3 #define ll long long
 4 namespace gengyf{
 5 inline int read(){
 6     int x=0,f=1;char s=getchar();
 7     while(s<‘0‘||s>‘9‘){if(s==‘-‘)f=-1;s=getchar();}
 8     while(s>=‘0‘&&s<=‘9‘){x=x*10+s-‘0‘;s=getchar();}
 9     return f*x;
10 }
11 ll n,k,ans;
12 ll lowbit(ll x){return x&-x;}
13 int main(){
14     n=read();k=read();
15     bitset<60>a(n);
16     while(a.count()>k){
17         ans+=lowbit(n);
18         n+=lowbit(n);
19         a=n;
20     }
21     printf("%lld",ans);
22     return 0;
23 }
24 /*
25  affection 挚爱
26  adopt 采纳
27  administration 管理
28  agent 代理
29 */
30 }
31 signed main(){
32     gengyf::main();
33     return 0;
34 }