BZOJ3236 [Ahoi2013]作业

昨天晚上做的。。。差错一直查到今天= =

最后没办法问管理员要了数据才知道原来ans数组开小了233，简直沙茶

这道题不就是裸的莫队嘛= =|||

只要用树状数组维护当前的两种个数即可。

  1 /**************************************************************
  2     Problem: 3236
  3     User: rausen
  4     Language: C++
  5     Result: Accepted
  6     Time:79318 ms
  7     Memory:66252 kb
  8 ****************************************************************/
  9  
 10 #include <cstdio>
 11 #include <cmath>
 12 #include <algorithm>
 13  
 14 #define lowbit(x) x & -x
 15 using namespace std;
 16 const int N = 100005;
 17 const int M = 1000005;
 18 const int Maxlen = 37000005;
 19  
 20 int n, size, Q;
 21 int BIT[2][N], cnt[N], pos[N], a[N];
 22 int ans1[M], ans2[M];
 23 int Len, Left;
 24 char buf[Maxlen];
 25  
 26 struct Query {
 27     int l, r, a, b, w;
 28 } q[M];
 29 inline bool operator < (const Query &a, const Query &b) {
 30     return pos[a.l] == pos[b.l] ? a.r < b.r : pos[a.l] < pos[b.l];
 31 }
 32 inline bool cmp_id (const Query &a, const Query &b) {
 33     return a.w < b.w;
 34 }
 35  
 36 inline int read() {
 37     int x = 0;
 38     while (buf[Left] < '0' || '9' < buf[Left])
 39         ++Left;
 40     while ('0' <= buf[Left] && buf[Left] <= '9')
 41         x = x * 10 + buf[Left++] - '0';
 42     return x;
 43 }
 44  
 45 int len = 0, pr[15];
 46 inline void print(int x) {
 47     while (x)
 48         pr[++len] = x % 10, x /= 10;
 49     if (!len) putchar('0');
 50     while (len)
 51         putchar(pr[len--] + '0');
 52 }
 53  
 54 inline void update(int x, int del, int T) {
 55     while (x <= n)
 56         BIT[T][x] += del, x += lowbit(x);
 57 }
 58  
 59 inline int query(int x, int T) {
 60     int res = 0;
 61     while (x)
 62         res += BIT[T][x], x -= lowbit(x);
 63     return res;
 64 }
 65  
 66 inline void update(int x, int del) {
 67     if (!cnt[x])
 68         update(x, 1, 1);
 69     cnt[x] += del;
 70     if (!cnt[x])
 71         update(x, -1, 1);
 72     update(x, del, 0);
 73 }
 74  
 75 int main() {
 76     int i, l, r;
 77     Len = fread(buf, 1, Maxlen, stdin);
 78     buf[Len] = ' ';
 79     n = read(), Q = read();
 80     size = (int) sqrt(n);
 81     for (i = 1; i <= n; ++i)
 82         a[i] = read(), pos[i] = i / size;
 83     for (i = 1; i <= Q; ++i) {
 84         q[i].l = read(), q[i].r = read();
 85         q[i].a = read(), q[i].b = read();
 86         q[i].w = i;
 87     }
 88      
 89     sort(q + 1, q + Q + 1);
 90     for (i = l = 1, r = 0; i <= Q; ++i) {
 91         for (; r < q[i].r; ) update(a[++r], 1);
 92         for (; r > q[i].r; ) update(a[r--], -1);
 93         for (; l < q[i].l; ) update(a[l++], -1);
 94         for (; l > q[i].l; ) update(a[--l], 1);
 95         ans1[q[i].w] = query(q[i].b, 0) - query(q[i].a - 1, 0);
 96         ans2[q[i].w] = query(q[i].b, 1) - query(q[i].a - 1, 1);
 97     }
 98     for (i = 1; i <= Q; ++i) {
 99         print(ans1[i]), putchar(' ');
100         print(ans2[i]), putchar('\r'), putchar('\n');
101     }
102     return 0;
103 }