UVa 11297 Census 二维线段树模板

来源：互联网发布：编程是什么编辑：程序博客网时间：2024/06/07 05:52

题目链接：https://vjudge.net/problem/UVA-11297

二维线段树模板题，单点修改与区间查询，这里按照刘汝佳说的加了个build函数，能起到一定的优化效果。

#include<cstdio>#include<cstring>#include<algorithm>using namespace std;const int INF = (1<<30);const int maxn = 2000 + 10;struct IntervalTree2D {  int Max[maxn][maxn], Min[maxn][maxn], n, m;  int xo, xleaf, x1, y1, x2, y2, x, y, v, vmax, vmin;  void build1D(int o, int L, int R) {    if(L == R) {      if(xleaf) { scanf("%d", &v); Max[xo][o] = Min[xo][o] = v; return; }      Max[xo][o] = max(Max[xo*2][o], Max[xo*2+1][o]);      Min[xo][o] = min(Min[xo*2][o], Min[xo*2+1][o]);    }    else {      int M = (L + R) >> 1;      build1D(o*2, L, M);      build1D(o*2+1, M+1, R);      Max[xo][o] = max(Max[xo][o*2], Max[xo][o*2+1]);      Min[xo][o] = min(Min[xo][o*2], Min[xo][o*2+1]);    }  }  void build2D(int o, int L, int R) {    if(L == R) {      xleaf = 1;      xo = o;      build1D(1, 1, m);    }    else {      int M = (L + R) >> 1;      build2D(o*2, L, M);      build2D(o*2+1, M+1, R);      xleaf = 0; xo = o; build1D(1, 1, m);    }  }  void query1D(int o, int L, int R) {    if(y1 <= L && R <= y2) {      vmax = max(vmax, Max[xo][o]);      vmin = min(vmin, Min[xo][o]);    }    else {      int M = (L + R) >> 1;      if(y1 <= M) query1D(o*2, L, M);      if(M < y2) query1D(o*2+1, M+1, R);    }  }  void query2D(int o, int L, int R) {    if(x1 <= L && R <= x2) {      xo = o;      query1D(1, 1, m);    }    else {      int M = (L + R) >> 1;      if(x1 <= M) query2D(o*2, L, M);      if(M < x2) query2D(o*2+1, M+1, R);    }  }  void modify1D(int o, int L, int R) {    if(L == R) {      if(xleaf) { Max[xo][o] = Min[xo][o] = v; return; }      Max[xo][o] = max(Max[xo*2][o], Max[xo*2+1][o]);      Min[xo][o] = min(Min[xo*2][o], Min[xo*2+1][o]);    }    else {      int M = (L + R) >> 1;      if(y <= M) modify1D(o*2, L, M);      else modify1D(o*2+1, M+1, R);      Max[xo][o] = max(Max[xo][o*2], Max[xo][o*2+1]);      Min[xo][o] = min(Min[xo][o*2], Min[xo][o*2+1]);    }  }  void modify2D(int o, int L, int R) {     if(L == R) {       xleaf = 1; xo = o; modify1D(1, 1, m);     }     else {        int M = (L + R) >> 1;        if(x <= M) modify2D(o*2, L, M);        else modify2D(o*2+1, M+1, R);        xo = o; xleaf = 0; modify1D(1, 1, m);     }  }  void modify() { modify2D(1, 1, n); }  void query() { vmax = -INF, vmin = INF; query2D(1, 1, n); }};IntervalTree2D t;int main() {  int n, m, Q, x1, y1, x2, y2, x, y, v;  char op[10];  scanf("%d", &n);  m = n;  t.n = n; t.m = n;  t.build2D(1, 1, n);  scanf("%d", &Q);  while(Q--) {    scanf("%s", op);    if(op[0] == 'q') {      scanf("%d%d%d%d", &t.x1, &t.y1, &t.x2, &t.y2);      t.query();      printf("%d %d\n", t.vmax, t.vmin);    }    else {      scanf("%d%d%d", &t.x, &t.y, &t.v);      t.modify();    }  }  return 0;}

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