A Bit Fun
Time Limit: 5000/2500 MS (Java/Others) Memory Limit: 32768/32768 K (Java/Others)
Total Submission(s): 2089 Accepted Submission(s): 1040
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
用个数组记录下各位出现的次数,就可以实现在一段区间或的值中减去一个元素。
代码:
#include <iostream> #include <cstdio> #include <cstring> #include <algorithm> #include <cmath> #include <queue> #include <vector> #include <string> #include <map> #include <cstdlib> #include <ctime> using namespace std; const int maxn=100000+1000; int a[maxn]; int h[100]; int n,m; void add(int x) { int cur=0; while(x) { h[cur++]+=(x%2); x=x/2; } } void del(int x) { int cur=0; while(x) { h[cur++]-=(x%2); x=x/2; } } int re() { int ans=0; for(int i=0; i<35; i++) { if(h[i]>0) ans+=(1<<i); } return ans; } int main() { int t,ca=1; scanf("%d",&t); while(t--) { scanf("%d%d",&n,&m); memset(h,0,sizeof(h)); for(int i=0; i<n; i++) scanf("%d",&a[i]); int temp=0; long long ans=0; int cur=0; for(int i=0; i<n; i++) { cur=max(i,cur); while((temp|a[cur])<m&&cur<n) { temp=(temp|a[cur]); add(a[cur]); cur++; } if(cur>i) { ans+=(cur-i); del(a[i]); temp=re(); } } printf("Case #%d: ",ca++); cout<<ans<<endl; } return 0; }