codeforces 399 B. Code For 1 归并

题意：给一个数n，和一个区间[l,r].数n可以做样的变化n=>  n/2,n%2,n/2  生成一个序列。如果序列中有大于等于2要继续生成，直到全部数小于2.求区间l，r上1的个数

#include<cstdio>#include<queue>#include<iostream>#include<vector>#include<map>#include<cstring>#include<string>#include<set>#include<stack>#include<algorithm>#define cle(a) memset(a,0,sizeof(a))#define inf(a) memset(a,ox3f,sizeof(a))#define ll long long#define Rep(i,a,n) for(int i=a;i<=n;i++)using namespace std;const int INF = ( 2e9 ) + 2;//const int maxn = ll query(ll L,ll R,ll l,ll r,ll a){if(l>R||r<L||a==0)return 0;if(a==1)return 1;ll mid=(L+R)>>1;return query(L,mid-1,l,r,a/2)+query(mid,mid,l,r,a%2)+query(mid+1,R,l,r,a/2);}int main(){ll n,l,r;//freopen("in.txt","r",stdin);scanf("%I64d%I64d%I64d",&n,&l,&r);ll len=1,x=n;while(x>1){len=2*len+1;x>>=1;}ll ans=query(1,len,l,r,n);printf("%I64d\n",ans);}