BZOJ 3781: 小B的询问

 1 #include <bits/stdc++.h>
 2 
 3 #define int long long
 4 
 5 typedef long long longint;
 6 
 7 const int siz = 50000 + 5;
 8 
 9 int n, m, k;
10 int l, r, s;
11 int num[siz];
12 int cnt[siz];
13 
14 longint sum = 0;
15 
16 struct query {
17     int l, r, id;
18     longint  ans;    
19 }qry[siz];
20 
21 inline bool cmp_lr(const query &a, const query &b) {
22     if (a.l / s != b.l / s)
23         return a.l < b.l;
24     else
25         return a.r < b.r;
26 }
27 
28 inline bool cmp_id(const query &a, const query &b) {
29     return a.id < b.id;
30 }
31 
32 inline longint sqr(int t) {
33     return t*t;
34 }
35 
36 inline void remove(int t) {
37 //    printf("r %d\n", t);
38     sum -= sqr(cnt[t]);
39     sum += sqr(--cnt[t]);
40 }
41 
42 inline void insert(int t) {
43 //    printf("i %d\n", t);
44     sum -= sqr(cnt[t]);
45     sum += sqr(++cnt[t]);
46 }
47 
48 inline void solve(query &q) {
49 //    printf("s %d %d\n", q.l, q.r);
50     while (l < q.l)remove(num[l++]);
51     while (l > q.l)insert(num[--l]);
52     while (r < q.r)insert(num[++r]);
53     while (r > q.r)remove(num[r--]);
54     q.ans = sum;
55 }
56 
57 signed main(void) {
58     scanf("%lld%lld%lld", &n, &m, &k); 
59     for (int i = 1; i <= n; ++i)
60         scanf("%lld", num + i);
61     for (int i = 1; i <= m; ++i) {
62         qry[i].id = i;
63         scanf("%lld%lld", 
64             &qry[i].l,
65             &qry[i].r);
66     }
67     s = sqrt(n); l = 1, r = 0;
68     std::sort(qry + 1, qry + 1 + m, cmp_lr);
69     for (int i = 1; i <= m; ++i)solve(qry[i]);
70     std::sort(qry + 1, qry + 1 + m, cmp_id);
71     for (int i = 1; i <= m; ++i)
72         printf("%lld\n", qry[i].ans);
73 }