1067: [SCOI2007]降雨量

题目链接

题目大意：给出若干年降雨量，判断一些话为真/假/不确定

题解：Orz huzecong

我的收获：神题跪跪跪

//Dalao的代码#include <cstdio>  #include <cstdlib>  #include <climits>  #include <algorithm>  #define N 100000  #define LOGN 18  int n, st[LOGN + 1][N + 1], q, x, y, d[N + 1], a[N + 1], ans, logn, Log[N + 1];  int query(int l, int r)  {      if (l > r) return INT_MIN;      int len = Log[r - l + 1];      return std::max(st[len][l], st[len][r - (1 << len) + 1]);  }  void build()  {      logn = Log[n];      for (int i = 0; i <= n; ++i) st[0][i] = a[i];      for (int i = 1; i <= logn; ++i)          for (int j = 1; j <= n - (1 << i) + 1; ++j)              st[i][j] = std::max(st[i - 1][j], st[i - 1][j + (1 << i - 1)]);  }  //lower_bound returns the first elements not less than x (>=)  inline int getpos(int x)  { return std::lower_bound(d + 1, d + n + 1, x) - d; }  int main()  {      for (int i = 1, j = 1, k = -1; i <= N; ++i)          if (i == j) Log[i] = ++k, j <<= 1;          else Log[i] = k;      scanf("%d", &n);      for (int i = 1; i <= n; ++i)          scanf("%d%d", d + i, a + i);      scanf("%d", &q);      build();      while (q--)      {          scanf("%d%d", &x, &y);          int l = getpos(x), r = getpos(y), m;          bool lx = l <= n && d[l] == x, rx = r <= n && d[r] == y;          if (!rx) --r;          if (lx)              if (rx)              {                  m = query(l + 1, r - 1);                  if (a[l] < a[r]) ans = 0;                  else                     if (m < a[r])                          if (r - l == y - x) ans = 1;                          else ans = -1;                      else ans = 0;              }              else             {                  m = query(l + 1, r);                  if (m < a[l]) ans = -1;                  else ans = 0;              }          else             if (rx)              {                  m = query(l, r - 1);                  if (m < a[r]) ans = -1;                  else ans = 0;              }              else ans = -1;          if (ans == 1) printf("true\n");          else if (!ans) printf("false\n");          else printf("maybe\n");      }      return 0;  }