uva 11645 - Bits(计数问题+高精度)

题目链接：uva
11645 - Bits

#include <cstdio>
#include <cstring>

typedef long long ll;
const int N = 100;
const ll M = 1e13;

ll bit (int k) {
return (ll)1<<k;
}

void add (ll& p, ll& q, ll a, ll b) {
if (a <= 0 || b <= 0)
return;

q += a * b;
p += q/M;
q %= M;
}

void solve (ll n) {

int j = 0;
ll left = n/2, right = 0;
ll p = 0, q = 0;

while (left) {

left /= 2;
add(p, q, left, bit(j));
if ((n&bit(j)) && (n&bit(j+1)))
add(p, q, 1, right+1);

if (n&bit(j))
right |= bit(j);
j++;
}

if (p) {
printf("%lld", p);
printf("%013lld\n", q);
} else {
printf("%lld\n", q);
}
}

int main () {
ll n;
int cas = 1;
while (scanf("%lld", &n) == 1 && n >= 0) {
printf("Case %d: ", cas++);
solve(n);
}
return 0;
}