【HDOJ】4553 约会安排

线段树。线段树的细节很重要，小数据遍历可以发现问题。

  1 /* 4553 */
  2 #include <iostream>
  3 #include <string>
  4 #include <map>
  5 #include <queue>
  6 #include <set>
  7 #include <stack>
  8 #include <vector>
  9 #include <deque>
 10 #include <algorithm>
 11 #include <cstdio>
 12 #include <cmath>
 13 #include <ctime>
 14 #include <cstring>
 15 #include <climits>
 16 #include <cctype>
 17 #include <cassert>
 18 #include <functional>
 19 #include <iterator>
 20 #include <iomanip>
 21 using namespace std;
 22 //#pragma comment(linker,"/STACK:102400000,1024000")
 23 
 24 #define sti                set<int>
 25 #define stpii            set<pair<int, int> >
 26 #define mpii            map<int,int>
 27 #define vi                vector<int>
 28 #define pii                pair<int,int>
 29 #define vpii            vector<pair<int,int> >
 30 #define rep(i, a, n)     for (int i=a;i<n;++i)
 31 #define per(i, a, n)     for (int i=n-1;i>=a;--i)
 32 #define clr                clear
 33 #define pb                 push_back
 34 #define mp                 make_pair
 35 #define fir                first
 36 #define sec                second
 37 #define all(x)             (x).begin(),(x).end()
 38 #define SZ(x)             ((int)(x).size())
 39 #define lson            l, mid, rt<<1
 40 #define rson            mid+1, r, rt<<1|1
 41 
 42 typedef struct {
 43     int l, r;
 44     int nls, nrs, nms;
 45     int dls, drs, dms;
 46 } node_t;
 47 
 48 const int study = 0;
 49 const int ds = 1;
 50 const int ns = 2;
 51 const int maxn = 1e5+5;
 52 node_t nd[maxn<<2];
 53 
 54 void Build(int l, int r, int rt) {
 55     nd[rt].l = l;
 56     nd[rt].r = r;
 57     nd[rt].nls = nd[rt].nrs = nd[rt].nms = r-l+1;
 58     nd[rt].dls = nd[rt].drs = nd[rt].dms = r-l+1;
 59     if (l == r)
 60         return ;
 61     
 62     int mid = (l + r) >> 1;
 63     Build(lson);
 64     Build(rson);
 65 }
 66 
 67 void PushDown(int rt) {
 68     int l = nd[rt].l, r = nd[rt].r;
 69     if (l == r)    return ;
 70     int lb = rt<<1;
 71     int rb = lb |1;
 72     int mid = (l + r) >> 1;
 73     
 74     if (nd[rt].dms == 0) {
 75         nd[lb].dls = nd[lb].drs = nd[lb].dms = 0;
 76         nd[rb].dls = nd[rb].drs = nd[rb].dms = 0;
 77     } else if (nd[rt].dms == r-l+1) {
 78         nd[lb].dls = nd[lb].drs = nd[lb].dms = mid - l + 1;
 79         nd[rb].dls = nd[rb].drs = nd[rb].dms = r - mid;
 80     }
 81     
 82     if (nd[rt].nms == 0) {
 83         nd[lb].nls = nd[lb].nrs = nd[lb].nms = 0;
 84         nd[rb].nls = nd[rb].nrs = nd[rb].nms = 0;
 85     } else if (nd[rt].nms == r-l+1) {
 86         nd[lb].nls = nd[lb].nrs = nd[lb].nms = mid - l + 1;
 87         nd[rb].nls = nd[rb].nrs = nd[rb].nms = r - mid;
 88     }
 89 }
 90 
 91 void PushUp1(int rt) {
 92     int l = nd[rt].l, r = nd[rt].r; 
 93     if (l == r)    return ;
 94     int lb = rt<<1;
 95     int rb = lb |1;
 96     int mid = (l + r) >> 1;
 97     
 98     nd[rt].dls = nd[lb].dls;
 99     nd[rt].drs = nd[rb].drs;
100     nd[rt].dms = max(nd[lb].dms, nd[rb].dms);
101     nd[rt].dms = max(nd[rt].dms, nd[lb].drs+nd[rb].dls);
102     
103     if (nd[lb].dls == mid - l + 1)
104         nd[rt].dls += nd[rb].dls;
105     if (nd[rb].drs == r - mid)
106         nd[rt].drs += nd[lb].drs;
107 }
108 
109 void PushUp2(int rt) {
110     int l = nd[rt].l, r = nd[rt].r;
111     if (l == r)    return ;
112     int lb = rt<<1;
113     int rb = lb |1;
114     int mid = (l + r) >> 1;
115     
116     nd[rt].nls = nd[lb].nls;
117     nd[rt].nrs = nd[rb].nrs;
118     nd[rt].nms = max(nd[lb].nms, nd[rb].nms);
119     nd[rt].nms = max(nd[rt].nms, nd[lb].nrs+nd[rb].nls);
120     
121     if (nd[lb].nls == mid - l + 1)
122         nd[rt].nls += nd[rb].nls;
123     if (nd[rb].nrs == r - mid)
124         nd[rt].nrs += nd[lb].nrs;
125 }
126 
127 int query1(int qt, int rt) {
128     PushDown(rt);
129     
130     if (nd[rt].dms < qt)
131         return 0;
132     
133     if (nd[rt].dls >= qt)
134         return nd[rt].l;
135     
136     if (nd[rt<<1].dms >= qt)
137         return query1(qt, rt<<1);
138     
139     if (nd[rt<<1].drs + nd[rt<<1|1].dls >= qt)
140         return nd[rt<<1].r - nd[rt<<1].drs + 1;
141     
142     return query1(qt, rt<<1|1);
143 }
144 
145 int query2(int qt, int rt) {
146     PushDown(rt);
147     
148     if (nd[rt].nms < qt)
149         return 0;
150     
151     if (nd[rt].nls >= qt)
152         return nd[rt].l;
153     
154     if (nd[rt<<1].nms >= qt)
155         return query2(qt, rt<<1);
156     
157     if (nd[rt<<1].nrs + nd[rt<<1|1].nls >= qt)
158         return nd[rt<<1].r - nd[rt<<1].nrs + 1;
159     
160     return query2(qt, rt<<1|1);
161 }
162 
163 void update0(int L, int R, int rt) {
164     if (L<=nd[rt].l && nd[rt].r<=R) {
165         nd[rt].nls = nd[rt].nrs = nd[rt].nms = nd[rt].r-nd[rt].l+1;
166         nd[rt].dls = nd[rt].drs = nd[rt].dms = nd[rt].r-nd[rt].l+1;
167         return ;
168     }
169     
170     PushDown(rt);
171     int mid = (nd[rt].l + nd[rt].r) >> 1;
172     
173     if (mid >= R) {
174         update0(L, R, rt<<1);
175     } else if (mid < L) {
176         update0(L, R, rt<<1|1);
177     } else {
178         update0(L, R, rt<<1);
179         update0(L, R, rt<<1|1);
180     }
181     
182     PushUp1(rt);
183     PushUp2(rt);
184 }
185 
186 void update1(int L, int R, int rt) {
187     if (L<=nd[rt].l && nd[rt].r<=R) {
188         nd[rt].dls = nd[rt].drs = nd[rt].dms = 0;
189         return ;
190     }
191     
192     PushDown(rt);
193     int mid = (nd[rt].l + nd[rt].r) >> 1;
194     
195     if (mid >= R) {
196         update1(L, R, rt<<1);
197     } else if (mid < L) {
198         update1(L, R, rt<<1|1);
199     } else {
200         update1(L, R, rt<<1);
201         update1(L, R, rt<<1|1);
202     }
203     
204     PushUp1(rt);
205 }
206 
207 void update2(int L, int R, int rt) {
208     if (L<=nd[rt].l && nd[rt].r<=R) {
209         nd[rt].nls = nd[rt].nrs = nd[rt].nms = 0;
210         nd[rt].dls = nd[rt].drs = nd[rt].dms = 0;
211         return ;
212     }
213     
214     PushDown(rt);
215     int mid = (nd[rt].l + nd[rt].r) >> 1;
216     
217     if (mid >= R) {
218         update2(L, R, rt<<1);
219     } else if (mid < L) {
220         update2(L, R, rt<<1|1);
221     } else {
222         update2(L, R, rt<<1);
223         update2(L, R, rt<<1|1);
224     }
225     
226     PushUp1(rt);
227     PushUp2(rt);
228 }
229 
230 int main() {
231     ios::sync_with_stdio(false);
232     #ifndef ONLINE_JUDGE
233         freopen("data.in", "r", stdin);
234         freopen("data.out", "w", stdout);
235     #endif
236     
237     int t;
238     int n, q;
239     int qt, l, r, ans;
240     char cmd[10];
241     
242     scanf("%d", &t);
243     rep(tt, 1, t+1) {
244         scanf("%d %d", &n, &q);
245         Build(1, n, 1);
246         printf("Case %d:\n", tt);
247         while (q--) {
248             scanf("%s", cmd);
249             if (cmd[0] == 'S') {
250                 scanf("%d %d", &l, &r);
251                 update0(l, r, 1);
252                 puts("I am the hope of chinese chengxuyuan!!");
253             } else if (cmd[0] == 'D') {
254                 scanf("%d", &qt);
255                 l = query1(qt, 1);
256                 if (l == 0) {
257                     puts("fly with yourself");
258                 } else {
259                     printf("%d,let's fly\n", l);
260                     update1(l, l+qt-1, 1);
261                 }
262             } else if (cmd[0] == 'N') {
263                 scanf("%d", &qt);
264                 l = query1(qt, 1);
265                 if (l == 0)
266                     l = query2(qt, 1);
267                 if (l == 0) {
268                     puts("wait for me");
269                 } else {
270                     printf("%d,don't put my gezi\n", l);
271                     update2(l, l+qt-1, 1);
272                 }
273             }
274         }
275     }
276     
277     #ifndef ONLINE_JUDGE
278         printf("time = %d.\n", (int)clock());
279     #endif
280     
281     return 0;
282 }

 

posted on 2015-10-25 13:17  Bombe  阅读(331)  评论(0)  编辑  收藏  举报

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