hdu 4419 线段树 扫描线 离散化 矩形面积

 //离散化 + 扫描线 + 线段树
 //这个线段树跟平常不太一样的地方在于记录了区间两个信息，len[i]表示颜色为i的被覆盖的长度为len[i]， num[i]表示颜色i 『完全』覆盖了该区间几层。len[i]起传递儿子与父亲的关系，而num[i]不起传递作用，只是单纯的表示被覆盖的区间。
 //然后就是pushUp函数，必须在update到底层后即更新num[]和len，然后把len传上去。
 //离散化后由于求的是面积，所以我是把每条长度为1的线段当做一个点， 即把左端点表示此段长度。而不是把点当成点。
 #include <iostream>
 #include <cstdio>
 #include <algorithm>
 #include <cstring>
 #include <cmath>

 using namespace std;
 #define lson l, m, rt<<1
 #define rson m + 1, r, rt<<1|1
 typedef long long ll;
 const int maxn = 2e4 + ;

 struct Seg{
     char c;
     int y, s, t, tag;
 }ss[maxn];
 bool cmp(Seg a, Seg b){
     return a.y < b.y;
 }
 int san[maxn], tot;
 int num[maxn << ][],len[maxn << ][];
 ll ans[];
 void pushUp(int l, int r, int rt){
     int state = (num[rt][] >  ?  : ) | (num[rt][] >  ?  : ) | (num[rt][] >  ?  : );
     memset(len[rt], , sizeof(len[rt]));
     if (state){
         len[rt][state] = san[r] - san[l - ];
         for (int i = ; i < ; ++i){
             if (state != (state|i)){
                 int tmp = len[rt<<][i] + len[rt<<|][i];
                 len[rt][state|i] += tmp;
                 len[rt][state] -= tmp;
             }
         }
     }
     else if (l != r){
         for (int i = ; i < ; ++i) len[rt][i] = len[rt<<][i] + len[rt<<|][i];
     }
 }
 int getC(char c){
     if (c == 'R') return ;
     if (c == 'G') return ;
     return ;
 }
 void update(int L, int R, char c, int tag, int l, int r, int rt){
     if (L <= l && R >= r){
         int cc = getC(c);
         num[rt][cc] += tag;
         //注意
         pushUp(l, r, rt);
         return ;
     }
     int m = (l + r) >> ;
     if (L <= m) update(L, R, c, tag, lson);
     if (R > m) update(L, R, c, tag, rson);
     pushUp(l, r, rt);
 }
 int T,  n;
 int main(){
     int tcas = ;
     int x1, x2, y1, y2;
     char s[];
     scanf("%d", &T);
     while (T--){
         scanf("%d", &n);
         tot = ;
         for (int i = ; i <= n; ++i){
             scanf("%s%d%d%d%d", s,&x1, &y1, &x2, &y2);
             ss[i].c = s[]; ss[i].y = y1; ss[i].s = x1; ss[i].t = x2, ss[i].tag= ;
             ss[i + n].c = s[]; ss[i + n].y = y2; ss[i + n].s = x1; ss[i + n].t = x2, ss[i + n].tag = -;
             san[tot++] = x1 ; san[tot++] = x2;
         }
         n = n * ;

         sort(san, san + tot);
         tot = unique(san, san + tot) - san;
         sort(ss + , ss + n + , cmp);
         ss[].y = ss[].y;

         memset(num, , sizeof(num));
         memset(len, , sizeof(len));
         memset(ans, , sizeof(ans));
         for (int i = ; i <= n; ++i){
             int l = lower_bound(san, san + tot, ss[i].s) - san + ;
             int r = lower_bound(san, san + tot, ss[i].t) - san;
             /*cout << " l = " << l << " r = " << r ;
             cout << " tag = " << ss[i].tag << " c = "<< ss[i].c << endl;
             for (int j = 1; j < 8; ++j) cout << len[1][j] << " ";
             cout << endl;
             cout << endl;
             */
             if (ss[i].y != ss[i - ].y){
                 for (int j = ; j < ; ++j){
                     ans[j] += (ll)(ss[i].y - ss[i - ].y) * (ll)len[][j];
                 }
             }
             update(l, r, ss[i].c, ss[i].tag, , tot - , );
         }
         printf("Case %d:\n", ++tcas);
         swap(ans[], ans[]);
         for (int i = ; i < ; ++i)
             printf("%lld\n", ans[i]);
     }
     return ;
 }