又是莫队= =
话说这题和"小z的袜子"有区别嘛= =
1 /************************************************************** 2 Problem: 3781 3 User: rausen 4 Language: C++ 5 Result: Accepted 6 Time:2212 ms 7 Memory:2380 kb 8 ****************************************************************/ 9 10 #include <cstdio> 11 #include <cmath> 12 #include <algorithm> 13 14 using namespace std; 15 typedef long long ll; 16 const int N = 50005; 17 18 int n, Q, c[N]; 19 int sz, pos[N]; 20 int l, r, cnt[N]; 21 ll sum, ans[N]; 22 23 struct query { 24 int l, r, id; 25 26 inline bool operator < (const query &b) const { 27 return pos[l] == pos[b.l] ? r < b.r : pos[l] < pos[b.l]; 28 } 29 } a[N]; 30 31 inline int read() { 32 int x = 0; 33 char ch = getchar(); 34 while (ch < '0' || '9' < ch) 35 ch = getchar(); 36 while ('0' <= ch && ch <= '9') { 37 x = x * 10 + ch - '0'; 38 ch = getchar(); 39 } 40 return x; 41 } 42 43 inline ll Sqr(int x) { 44 return (ll) x * x; 45 } 46 47 inline void update(int x, int d) { 48 sum -= (ll) Sqr(cnt[x]); 49 cnt[x] += d; 50 sum += (ll) Sqr(cnt[x]); 51 } 52 53 int main() { 54 int i; 55 n = read(), Q = read(), read(); 56 for (i = 1; i <= n; ++i) 57 c[i] = read(); 58 sz = (int) sqrt(n); 59 for (i = 1; i <= n; ++i) 60 pos[i] = (i - 1) / sz + 1; 61 for (i = 1; i <= Q; ++i) 62 a[i].l = read(), a[i].r = read(), a[i].id = i; 63 sort(a + 1, a + Q + 1); 64 for (i = 1, l = 1, r = 0; i <= Q; ++i) { 65 while (r < a[i].r) update(c[++r], 1); 66 while (r > a[i].r) update(c[r--], -1); 67 while (l > a[i].l) update(c[--l], 1); 68 while (l < a[i].l) update(c[l++], -1); 69 ans[a[i].id] = sum; 70 } 71 for (i = 1; i <= Q; ++i) 72 printf("%lld ", ans[i]); 73 return 0; 74 }
（p.s. 直接Rank倒3，蒟蒻被踩烂了= =）