HDU - 4777 离线树状数组

离线树状数组搞一搞。

#include<bits/stdc++.h>
#define LL long long
#define fi first
#define se second
#define mk make_pair
#define PII pair<int, int>
#define PLI pair<LL, int>
#define ull unsigned long long
using namespace std;

const int N = 2e5 + ;
const int inf = 0x3f3f3f3f;
const LL INF = 0x3f3f3f3f3f3f3f3f;
const int mod = ;
const int Mod = 1e9 + ;

int n, m, a[N], ans[N], L[N];
bool vis[N], is[N], ok[N];
vector<PII> v[N];
vector<int> p[N];
map<int,int> mp;

struct BIT {
    int a[N];
    void init() {
        for(int i = ; i <= n; i++) a[i] = ;
    }
    void modify(int x, int val) {
        for(int i = x; i <= n; i += i & -i)
            a[i] += val;
    }
    int sum(int x) {
        int ans = ;
        for(int i = x; i; i -= i & -i)
            ans += a[i];
        return ans;
    }
    int query(int l, int r) {
        return sum(r) - sum(l - );
    }
} b, c;

int main() {
    for(int i = ; i < N; i++) {
        if(is[i]) continue;
        for(int j = i; j < N; j += i) {
            is[j] = true;
            p[j].push_back(i);
        }
    }
    while(scanf("%d%d", &n, &m)!= EOF && (n || m)) {
        b.init(); mp.clear(); c.init();
        for(int i = ; i <= n; i++) {
            v[i].clear();
            vis[i] = ok[i] = true;
            scanf("%d", &a[i]);
            b.modify(i, );
            L[i] = inf;
        }
        for(int i = ; i <= m; i++) {
            int l, r;
            scanf("%d%d", &l, &r);
            v[l].push_back(mk(r, i));
        }
        for(int i = n; i >= ; i--) {
            for(int t : p[a[i]]) {
                if(mp.find(t) != mp.end()) {
                    int pos = mp[t];
                    L[i] = min(L[i], pos);
                    if(vis[pos]) {
                        vis[pos] = false;
                        b.modify(pos, -);
                    } else if(ok[pos] && L[pos] != inf){
                        ok[pos] = false;
                        c.modify(pos, -);
                        c.modify(L[pos], );
                    }
                }
                mp[t] = i;
            }
            if(L[i] != inf) {
                vis[i] = false;
                b.modify(i, -);
                c.modify(i, );
                c.modify(L[i], -);
            }
            for(PII t : v[i]) {
                ans[t.se] = b.query(i, t.fi) + c.sum(t.fi);
            }
        }
        for(int i = ; i <= m; i++) printf("%d\n", ans[i]);
    }
    return ;
}

/**/