HDU 4737 A Bit Fun (2013成都网络赛)

A Bit Fun

Time Limit: 5000/2500 MS (Java/Others)    Memory Limit: 32768/32768 K (Java/Others)
Total Submission(s): 423    Accepted Submission(s): 270

Problem Description
There are n numbers in a array, as a0, a1 ... , an-1, and another number m. We define a function f(i, j) = ai|ai+1|ai+2| ... | aj . Where "|" is the bit-OR operation. (i <= j)
The problem is really simple: please count the number of different pairs of (i, j) where f(i, j) < m.
 
Input
The first line has a number T (T <= 50) , indicating the number of test cases.
For each test case, first line contains two numbers n and m.(1 <= n <= 100000, 1 <= m <= 230) Then n numbers come in the second line which is the array a, where 1 <= ai <= 230.
 
Output
For every case, you should output "Case #t: " at first, without quotes. The t is the case number starting from 1.
Then follows the answer.
 
Sample Input
2
3 6
1 3 5
2 4
5 4
 
Sample Output
Case #1: 4
Case #2: 0
 
Source
 
Recommend
liuyiding
 

用位数num维护l,r两个指针。

扫描一遍。

复杂度31*n

 /* ***********************************************
Author :kuangbin
Created Time :2013/9/14 星期六 11:59:04
File Name :2013成都网络赛\1010.cpp
************************************************ */ #pragma comment(linker, "/STACK:1024000000,1024000000")
#include <stdio.h>
#include <string.h>
#include <iostream>
#include <algorithm>
#include <vector>
#include <queue>
#include <set>
#include <map>
#include <string>
#include <math.h>
#include <stdlib.h>
#include <time.h>
using namespace std;
const int MAXN = ;
int a[MAXN];
int num[];
int bit[]; int main()
{
//freopen("in.txt","r",stdin);
//freopen("out.txt","w",stdout); int T;
int n,m;
bit[] = ;
for(int i = ;i <= ;i++)
bit[i] = *bit[i-];
scanf("%d",&T);
int iCase = ;
while(T--)
{
iCase++;
scanf("%d%d",&n,&m);
for(int i = ;i < n;i++)
scanf("%d",&a[i]);
long long tot = (long long)n*(n+)/;
int last = ;
int i = ,j = ;
memset(num,,sizeof(num));
long long sum = ;
while(j < n)
{
for(int k = ;k <=;k++)
if(a[j] & bit[k])
num[k]++;
int s = ;
for(int k = ;k <= ;k++)
if(num[k])
s += bit[k];
if(s >= m)
{
while(s >=m)
{
for(int k = ;k <= ;k++)
if(a[i] & bit[k])
num[k]--;
s = ;
for(int k = ;k <= ;k++)
if(num[k])
s += bit[k];
i++;
//cout<<i<<endl;
}
sum += (long long)(n-j)*(i-last);
last = i;
}
j++;
}
printf("Case #%d: ",iCase);
//cout<<tot<<" "<<sum<<endl;
cout<<tot-sum<<endl;
}
return ;
}
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