# BZOJ1672: [Usaco2005 Dec]Cleaning Shifts 清理牛棚

## 1672: [Usaco2005 Dec]Cleaning Shifts 清理牛棚

Time Limit: 5 Sec  Memory Limit: 64 MB
Submit: 414  Solved: 191
[Submit][Status]

## Description

Farmer John's cows, pampered since birth, have reached new heights of fastidiousness. They now require their barn to be immaculate. Farmer John, the most obliging of farmers, has no choice but hire some of the cows to clean the barn. Farmer John has N (1 <= N <= 10,000) cows who are willing to do some cleaning. Because dust falls continuously, the cows require that the farm be continuously cleaned during the workday, which runs from second number M to second number E during the day (0 <= M <= E <= 86,399). Note that the total number of seconds during which cleaning is to take place is E-M+1. During any given second M..E, at least one cow must be cleaning. Each cow has submitted a job application indicating her willingness to work during a certain interval T1..T2 (where M <= T1 <= T2 <= E) for a certain salary of S (where 0 <= S <= 500,000). Note that a cow who indicated the interval 10..20 would work for 11 seconds, not 10. Farmer John must either accept or reject each individual application; he may NOT ask a cow to work only a fraction of the time it indicated and receive a corresponding fraction of the salary. Find a schedule in which every second of the workday is covered by at least one cow and which minimizes the total salary that goes to the cows.

约翰的奶牛们从小娇生惯养，她们无法容忍牛棚里的任何脏东西．约 翰发现，如果要使这群有洁癖的奶牛满意，他不得不雇佣她们中的一些来清扫牛棚, 约翰的奶牛中有N(1≤N≤10000)头愿意通过清扫牛棚来挣一些零花 钱．由于在某个时段中奶牛们会在牛棚里随时随地地乱扔垃圾，自然地，她们要求在这段时间里，无论什么时候至少要有一头奶牛正在打扫．需要打扫的时段从某一 天的第M秒开始，到第E秒结束f0≤M≤E≤86399)．注意这里的秒是指时间段而不是时间点，也就是说，每天需要打扫的总时间是E-M+I秒． 约翰已经从每头牛那里得到了她们愿意接受的工作计划：对于某一头牛，她每天都愿意在笫 Ti，.T2秒的时间段内工作(M≤Ti≤马≤E)，所要求的报酬是S美元(0≤S≤500000)．与需打扫时段的描述一样，如果一头奶牛愿意工作的时 段是每天的第10_20秒，那她总共工作的时间是11秒，而不是10秒．约翰一旦决定雇佣某一头奶牛，就必须付给她全额的工资，而不能只让她工作一段时 间，然后再按这段时间在她愿意工作的总时间中所占的百分比来决定她的工资．现在请你帮约翰决定该雇佣哪些奶牛以保持牛棚的清洁，当然，在能让奶牛们满意的 前提下，约翰希望使总花费尽量小．

## Input

* Line 1: Three space-separated integers: N, M, and E. * Lines 2..N+1: Line i+1 describes cow i's schedule with three space-separated integers: T1, T2, and S.

第1行：3个正整数N，M，E，用空格隔开．
第2到N+1行：第i+l行给出了编号为i的奶牛的工作计划，即3个用空格隔开的正整数Ti，T2，S．

## Output

* Line 1: a single integer that is either the minimum total salary to get the barn cleaned or else -1 if it is impossible to clean the barn.

输出一个整数，表示约翰需要为牛棚清理工作支付的最少费用．如果清理工作不可能完成，

## Sample Input

3 0 4 //三头牛,要打扫从0到4号stall
0 2 3 //一号牛,从0号stall打扫到2号,工资为3
3 4 2
0 0 1

INPUT DETAILS:

FJ has three cows, and the barn needs to be cleaned from second 0 to second
4. The first cow is willing to work during seconds 0, 1, and 2 for a total
salary of 3, etc.

5

## Source

Silver

f[i]表示到i时刻的最小代价，那么对于一只l-r费用c的牛

（不知道哪里写残了T_T）

  1 #include<cstdio>
2
3 #include<cstdlib>
4
5 #include<cmath>
6
7 #include<cstring>
8
9 #include<algorithm>
10
11 #include<iostream>
12
13 #include<vector>
14
15 #include<map>
16
17 #include<set>
18
19 #include<queue>
20
21 #include<string>
22
23 #define inf 100000000000
24
25 #define maxn 80000+2000
26
27 #define maxm 500+100
28
29 #define eps 1e-10
30
31 #define ll long long
32
33 #define pa pair<int,int>
34
35 #define for0(i,n) for(int i=0;i<=(n);i++)
36
37 #define for1(i,n) for(int i=1;i<=(n);i++)
38
39 #define for2(i,x,y) for(int i=(x);i<=(y);i++)
40
41 #define for3(i,x,y) for(int i=(x);i>=(y);i--)
42
43 #define mod 1000000007
44
45 using namespace std;
46
48
49 {
50
51     int x=0,f=1;char ch=getchar();
52
53     while(ch<'0'||ch>'9'){if(ch=='-')f=-1;ch=getchar();}
54
55     while(ch>='0'&&ch<='9'){x=10*x+ch-'0';ch=getchar();}
56
57     return x*f;
58
59 }
60
61 struct rec{int l,r;ll w;}a[maxn];
62
63 struct seg{int l,r;ll mi,tag;}t[4*maxn];
64
65 int n,x,y;
66
67 inline bool cmp(rec a,rec b)
68
69 {
70
71     return a.l<b.l||(a.l==b.l&&a.r<b.r);
72
73 }
74
75 inline void pushup(int k)
76
77 {
78
79     t[k].mi=min(t[k<<1].mi,t[k<<1|1].mi);
80
81 }
82
83 inline void update(int k,ll z)
84
85 {
86
87     t[k].mi=min(t[k].mi,z);
88
89     t[k].tag=min(t[k].tag,z);
90
91 }
92
93 inline void pushdown(int k)
94
95 {
96
97     if(t[k].tag==-1)return ;
98
99     update(k<<1,t[k].tag);
100
101     update(k<<1|1,t[k].tag);
102
103     t[k].tag=-1;
104
105 }
106
107 inline void build(int k,int x,int y)
108
109 {
110
111     int l=t[k].l=x,r=t[k].r=y,mid=(l+r)>>1;t[k].tag=-1;
112
113     if(l==r){t[k].mi=l==0?0:inf;return ;}
114
115     build(k<<1,l,mid);build(k<<1|1,mid+1,r);
116
117     pushup(k);
118
119 }
120
121 inline ll query(int k,int x)
122
123 {
124
125     int l=t[k].l,r=t[k].r,mid=(l+r)>>1;
126
127     if(l==r)return t[k].mi;
128
129     pushdown(k);
130
131     if(x<=mid)return query(k<<1,x);else return query(k<<1|1,x);
132
133 }
134
135 inline void change(int k,int x,int y,ll z)
136
137 {
138
139     int l=t[k].l,r=t[k].r,mid=(l+r)>>1;
140
141     if(l==x&&r==y){update(k,z);return;}
142
143     pushdown(k);
144
145     if(y<=mid)change(k<<1,x,y,z);
146
147     else if(x>mid)change(k<<1|1,x,y,z);
148
149     else change(k<<1,x,mid,z),change(k<<1|1,mid+1,y,z);
150
151     pushup(k);
152
153 }
154
155 int main()
156
157 {
158
159     freopen("input.txt","r",stdin);
160
161     freopen("output.txt","w",stdout);
162
164
165     for1(i,n)
166
167      {
168
170
171       if(a[i].l<=0)a[i].l=1;
172
173      }
174
175     sort(a+1,a+n+1,cmp);
176
177     build(1,0,y-x+1);
178
179     for1(i,n)
180
181     {
182
183         if(a[i].r<a[i].l)continue;
184
185         if(a[i].r<=0)continue;
186
187         if(a[i].l>y-x+1)continue;
188
189         ll t=query(1,a[i].l-1);
190
191         if(t!=inf)change(1,a[i].l,min(a[i].r,y-x+1),t+a[i].w);else break;
192
193     }
194
195     //for1(i,n)cout<<a[i].l<<' '<<a[i].r<<' '<<a[i].w<<endl;
196
197     //for1(k,8*n)cout<<t[k].l<<' '<<t[k].r<<' '<<t[k].mi<<' '<<t[k].tag<<endl;
198
199     ll ans=query(1,y-x+1);
200
201     printf("%lld\n",ans==inf?-1:ans);
202
203     return 0;
204
205 }
View Code

hzwer的

 1 #include<iostream>
2 #include<cstdio>
3 #include<cstring>
4 #include<cmath>
5 #include<algorithm>
6 #define ll long long
7 #define inf 10000000000
8 using namespace std;
10 {
11     int x=0,f=1;char ch=getchar();
12     while(ch<'0'||ch>'9'){if(ch=='-')f=-1;ch=getchar();}
13     while(ch>='0'&&ch<='9'){x=x*10+ch-'0';ch=getchar();}
14     return x*f;
15 }
16 int n,bg,ed;
17 struct seg{int l,r;ll tag,mn;}t[400005];
18 struct data{int t1,t2,c;}a[10005];
19 inline bool operator<(data a,data b)
20 {
21     return a.t1<b.t1;
22 }
23 void pushdown(int k)
24 {
25     if(t[k].l==t[k].r)return;
26     ll tag=t[k].tag;t[k].tag=inf;
27     if(tag!=inf)
28     {
29         t[k<<1].tag=min(t[k<<1].tag,tag);
30         t[k<<1|1].tag=min(t[k<<1|1].tag,tag);
31         t[k<<1].mn=min(t[k<<1].mn,tag);
32         t[k<<1|1].mn=min(t[k<<1|1].mn,tag);
33     }
34 }
35 void build(int k,int l,int r)
36 {
37     t[k].l=l;t[k].r=r;t[k].mn=inf;t[k].tag=inf;
38     if(l==r)return;
39     int mid=(l+r)>>1;
40     build(k<<1,l,mid);build(k<<1|1,mid+1,r);
41 }
42 ll query(int k,int x)
43 {
44     pushdown(k);
45     if(x<bg)return 0;
46     int l=t[k].l,r=t[k].r;
47     if(l==r)return t[k].mn;
48     int mid=(l+r)>>1;
49     if(x<=mid)return query(k<<1,x);
50     else return query(k<<1|1,x);
51 }
52 void update(int k,int x,int y,ll val)
53 {
54     pushdown(k);
55     int l=t[k].l,r=t[k].r;
56     if(x==l&&y==r)
57     {
58         t[k].tag=val;
59         t[k].mn=min(t[k].mn,val);
60         return;
61     }
62     int mid=(l+r)>>1;
63     if(y<=mid)update(k<<1,x,y,val);
64     else if(x>mid)update(k<<1|1,x,y,val);
65     else
66     {
67         update(k<<1,x,mid,val);
68         update(k<<1|1,mid+1,y,val);
69     }
70 }
71 int main()
72 {
74     build(1,bg,ed);
75     for(int i=1;i<=n;i++)
77     sort(a+1,a+n+1);
78     for(int i=1;i<=n;i++)
79     {
80         int t1=a[i].t1,t2=a[i].t2,c=a[i].c;
81         ll tmp=query(1,t1-1);
82         if(tmp==inf){puts("-1");return 0;}
83         update(1,t1,t2,tmp+c);
84     }
85     ll ans=query(1,ed);
86     if(ans<inf)printf("%lld",ans);
87     else puts("-1");
88     return 0;
89 }
View Code

我是sb，刚开始线段树的懒惰标记设为-1，简直没救。。。

  1 #include<cstdio>
2 #include<cstdlib>
3 #include<cmath>
4 #include<cstring>
5 #include<algorithm>
6 #include<iostream>
7 #include<vector>
8 #include<map>
9 #include<set>
10 #include<queue>
11 #include<string>
12 #define inf 100000000000
13 #define maxn 80000+2000
14 #define maxm 500+100
15 #define eps 1e-10
16 #define ll long long
17 #define pa pair<int,int>
18 #define for0(i,n) for(int i=0;i<=(n);i++)
19 #define for1(i,n) for(int i=1;i<=(n);i++)
20 #define for2(i,x,y) for(int i=(x);i<=(y);i++)
21 #define for3(i,x,y) for(int i=(x);i>=(y);i--)
22 #define mod 1000000007
23 using namespace std;
25 {
26     int x=0,f=1;char ch=getchar();
27     while(ch<'0'||ch>'9'){if(ch=='-')f=-1;ch=getchar();}
28     while(ch>='0'&&ch<='9'){x=10*x+ch-'0';ch=getchar();}
29     return x*f;
30 }
31 struct rec{int l,r;ll w;}a[maxn];
32 struct seg{int l,r;ll mi,tag;}t[4*maxn];
33 int n,x,y;
34 inline bool cmp(rec a,rec b)
35 {
36     return a.l<b.l||(a.l==b.l&&a.r<b.r);
37 }
38 inline void pushup(int k)
39 {
40     t[k].mi=min(t[k<<1].mi,t[k<<1|1].mi);
41 }
42 inline void update(int k,ll z)
43 {
44     t[k].mi=min(t[k].mi,z);
45     t[k].tag=min(t[k].tag,z);
46 }
47 inline void pushdown(int k)
48 {
49     if(t[k].tag==inf)return ;
50     update(k<<1,t[k].tag);
51     update(k<<1|1,t[k].tag);
52     t[k].tag=inf;
53 }
54 inline void build(int k,int x,int y)
55 {
56     int l=t[k].l=x,r=t[k].r=y,mid=(l+r)>>1;t[k].tag=inf;
57     if(l==r){t[k].mi=l==0?0:inf;return ;}
58     build(k<<1,l,mid);build(k<<1|1,mid+1,r);
59     pushup(k);
60 }
61 inline ll query(int k,int x)
62 {
63     int l=t[k].l,r=t[k].r,mid=(l+r)>>1;
64     if(l==r)return t[k].mi;
65     pushdown(k);
66     if(x<=mid)return query(k<<1,x);else return query(k<<1|1,x);
67 }
68 inline void change(int k,int x,int y,ll z)
69 {
70     int l=t[k].l,r=t[k].r,mid=(l+r)>>1;
71     if(l==x&&r==y){update(k,z);return;}
72     pushdown(k);
73     if(y<=mid)change(k<<1,x,y,z);
74     else if(x>mid)change(k<<1|1,x,y,z);
75     else change(k<<1,x,mid,z),change(k<<1|1,mid+1,y,z);
76     pushup(k);
77 }
78 int main()
79 {
80     freopen("input.txt","r",stdin);
81     freopen("output.txt","w",stdout);
83     for1(i,n)
84      {
86       if(a[i].l<=0)a[i].l=1;
87      }
88     sort(a+1,a+n+1,cmp);
89     build(1,0,y-x+1);
90     for1(i,n)
91     {
92         if(a[i].r<a[i].l)continue;
93         if(a[i].r<=0)continue;
94         if(a[i].l>y-x+1)continue;
95         ll t=query(1,a[i].l-1);
96         if(t!=inf)change(1,a[i].l,min(a[i].r,y-x+1),t+a[i].w);
97     }
98     //for1(i,n)cout<<a[i].l<<' '<<a[i].r<<' '<<a[i].w<<endl;
99     //for1(k,8*n)cout<<t[k].l<<' '<<t[k].r<<' '<<t[k].mi<<' '<<t[k].tag<<endl;
100     ll ans=query(1,y-x+1);
101     printf("%lld\n",ans==inf?-1:ans);
102     return 0;
103 }
View Code

posted @ 2014-09-25 13:11  ZYF-ZYF  Views(149)  Comments(0Edit  收藏  举报