标签:style http color os io ar for sp on
题目大意:给定一个长度为n的序列,现在问说有多少对i,j满足 f(i,j)<m.
解题思路: Twopointer,将每个数拆分成二进制形式,然后维护连个指针l,r,保证f(l, r) < m,那么当i = l时,对应的j就有r - l + 1种选择方法。
#include <cstdio>
#include <cstring>
#include <algorithm>
using namespace std;
typedef long long ll;
const int maxn = 100005;
int c[35], arr[maxn];
int add (int x, int v) {
int ret = 0;
for (int i = 0; i <= 30; i++) {
if (x&(1<<i))
c[i] += v;
if (c[i])
ret |= (1<<i);
}
return ret;
}
ll solve () {
ll ret = 0;
memset(c, 0, sizeof(c));
int l = 0, n, m, x, s = 0;
scanf("%d%d", &n, &m);
for (int i = 0; i < n; i++) {
scanf("%d", &arr[i]);
s = add(arr[i], 1);
while (s >= m)
s = add(arr[l++], -1);
ret += (i - l + 1);
}
return ret;
}
int main () {
int cas;
scanf("%d", &cas);
for (int kcas = 1; kcas <= cas; kcas++) {
ll ans = solve();
printf("Case #%d: %I64d\n", kcas, ans);
}
return 0;
}
hdu 4737 A Bit Fun(TwoPointer)
标签:style http color os io ar for sp on
原文地址:http://blog.csdn.net/keshuai19940722/article/details/39136283