51nod 1674 区间的价值V2(思维+拆位+尺取法)

# include <cstdio>
# include <cstring>
# include <cstdlib>
# include <iostream>
# include <vector>
# include <queue>
# include <stack>
# include <map>
# include <bitset>
# include <set>
# include <cmath>
# include <algorithm>
using namespace std;
# define lowbit(x) ((x)&(-x))
# define pi acos(-1.0)
# define eps 1e-8
# define MOD 1000000007
# define INF 1000000000
# define mem(a,b) memset(a,b,sizeof(a))
# define FOR(i,a,n) for(int i=a; i<=n; ++i)
# define FO(i,a,n) for(int i=a; i<n; ++i)
# define bug puts("H");
# define lch p<<1,l,mid
# define rch p<<1|1,mid+1,r
# define mp make_pair
# define pb push_back
typedef pair<int,int> PII;
typedef vector<int> VI;
# pragma comment(linker, "/STACK:1024000000,1024000000")
typedef long long LL;
inline int Scan() {
    int 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*10+ch-‘0‘; ch=getchar();}
    return x*f;
}
inline void Out(int a) {
    if(a<0) {putchar(‘-‘); a=-a;}
    if(a>=10) Out(a/10);
    putchar(a%10+‘0‘);
}
const int N=100005;
//Code begin...

int R[32][N], L[32][N], n, mod[65];
LL ans;
bool wei[32][N];

void init(){
    mod[0]=1; FOR(i,1,64) mod[i]=(mod[i-1]<<1)%MOD;
    FO(i,0,32) {
        int l=1, r=1;
        while (l<=n) {
            if (!wei[i][l]) L[i][l]=0;
            else {
                r=max(r,l);
                while (r<n&&wei[i][r+1]) ++r;
                L[i][l]=r;
            }
            ++l;
        }
    }
    FO(i,0,32) {
        int l=1, r=1;
        while (l<=n) {
            if (wei[i][l]) R[i][l]=l;
            else {
                r=max(l,r);
                while (r<=n&&!wei[i][r]) ++r;
                R[i][l]=r;
            }
            ++l;
        }
    }
}
void sol(){
    FO(i,0,32) FOR(j,1,n) {
        if (!wei[i][j]) continue;
        FO(k,0,32) {
            if (R[k][j]>L[i][j]) continue;
            ans=(ans+(LL)(L[i][j]-R[k][j]+1)*mod[i+k])%MOD;
        }
    }
}
int main ()
{
    int x;
    n=Scan();
    FOR(i,1,n) {
        x=Scan();
        FO(j,0,32) wei[j][i]=x%2, x/=2;
    }
    init();
    sol();
    printf("%lld\n",ans);
    return 0;
}