B. Rock and Lever 【位运算】1200
解法
, 只用考虑前面有多少个满足条件。
考虑aj最高位1在h,如果ai的最高位在h之前,或者在h之后,那么异或的值都大于并的值,所以要让并且大于异或,就必须是ai的最高位1也在h
。
代码
#include <bits/stdc++.h> #define ios ios_base::sync_with_stdio(0),cin.tie(0),cout.tie(0) #define debug_in freopen("in.txt","r",stdin) #define debug_out freopen("out.txt","w",stdout); #define pb push_back #define all(x) x.begin(),x.end() #define fs first #define sc second using namespace std; typedef long long ll; typedef unsigned long long ull; typedef pair<ll,ll> pii; const ll maxn = 1e6+10; const ll maxM = 1e6+10; const ll inf = 1e8; const ll inf2 = 1e17; template<class T>void read(T &x){ T s=0,w=1; char ch=getchar(); while(ch<'0'||ch>'9'){if(ch=='-')w=-1;ch=getchar();} while(ch>='0'&&ch<='9') s=s*10+ch-'0',ch=getchar(); x = s*w; } template<class H, class... T> void read(H& h, T&... t) { read(h); read(t...); } template <typename ... T> void DummyWrapper(T... t){} template <class T> T unpacker(const T& t){ cout<<' '<<t; return t; } template <typename T, typename... Args> void pt(const T& t, const Args& ... data){ cout << t; DummyWrapper(unpacker(data)...); cout << '\n'; } //-------------------------------------------- int T,N; int cnt[50]; int a[maxn]; void solve(){ ll ans = 0; for(int i = 1;i<=N;i++){ int high = -1; for(int j = 31;j>=0;j--){ if((a[i]>>j)& 1){ high = j; break; } } ans += cnt[high]; cnt[high]++; } printf("%lld\n",ans); } int main(){ // debug_in; read(T); while(T--){ read(N); for(int i = 0;i<40;i++) cnt[i] = 0; for(int i = 1;i<=N;i++) read(a[i]); solve(); } return 0; }