[SDOI2014]数表
[SDOI2014]数表
https://ac.nowcoder.com/acm/problem/20367
[SDOI2014]数表
/*
Author : lifehappy
*/
#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
const int N = 1e5 + 10;
int prime[N], mu[N], ans[N], tree[N], cnt;
bool st[N];
struct Node {
int id, sigma;
bool operator < (const Node &T) const {
return sigma < T.sigma;
}
}a[N];
struct Ask {
int n, m, a, id;
bool operator < (const Ask &T) const {
return a < T.a;
}
}ask[N];
void init() {
mu[1] = 1;
for(int i = 2; i < N; i++) {
if(!st[i]) {
prime[++cnt] = i;
mu[i] = -1;
}
for(int j = 1; j <= cnt && 1ll * i * prime[j] < N; j++) {
st[i * prime[j]] = 1;
if(i % prime[j] == 0) {
break;
}
mu[i * prime[j]] = -mu[i];
}
}
for(int i = 1; i < N; i++) {
a[i].id = i;
for(int j = i; j < N; j += i) {
a[j].sigma += i;
}
}
}
int lowbit(int x) {
return (-x) & x;
}
void update(int x, int value) {
while(x < N) {
tree[x] += value;
x += lowbit(x);
}
}
int query(int x) {
int ans = 0;
while(x) {
ans += tree[x];
x -= lowbit(x);
}
return ans;
}
int calc(int n, int m) {
if(n > m) swap(n, m);
int ans = 0;
for(int l = 1, r; l <= n; l = r + 1) {
r = min(n / (n / l), m / (m / l));
ans = ans + (n / l) * (m / l) * (query(r) - query(l - 1));
}
return ans;
}
int main() {
// freopen("in.txt", "r", stdin);
// freopen("out.txt", "w", stdout);
// ios::sync_with_stdio(false), cin.tie(0), cout.tie(0);
init();
int Q;
scanf("%d", &Q);
for(int i = 1; i <= Q; i++) {
scanf("%d %d %d", &ask[i].n, &ask[i].m, &ask[i].a);
ask[i].id = i;
}
sort(ask + 1, ask + 1 + Q);
sort(a + 1, a + N);
int pos = 1;
for(int i = 1; i <= Q; i++) {
while(pos < N && a[pos].sigma <= ask[i].a) {
for(int j = a[pos].id; j < N; j += a[pos].id) {
update(j, a[pos].sigma * mu[j / a[pos].id]);
}
pos++;
}
ans[ask[i].id] = calc(ask[i].n, ask[i].m);
}
for(int i = 1; i <= Q; i++) {
printf("%d\n", ans[i] & ((1ll << 31) - 1));
}
return 0;
}
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