对于全部的数据，1<=N、M、K<=50000

 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     else25         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 }