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10.22 比赛总结 修剪草坪(mowlawn)、玉米迷宫(cornmaze)

地址：http://pan.baidu.com/s/1hq03BIO

 

T1：之前想错了= =  f[i]表示前i位，且第i位不选的最小价值   f[i]=min{f[j]+A[i]} ，那么ans=TOT-f[i] n-k<i<n

      正着想f[i]=max{f[j-1]+sum[i]-sum[j],f[i-1]}也可以用单调队列维护

#include<set>
#include<map>
#include<cstdio>
#include<cstdlib>
#include<cstring>
#include<iostream>
#include<algorithm>
using namespace std;
const int N = 100010;
typedef long long lld;
#define inf 2147483647777777
#define For(i,n) for(int i=1;i<=n;i++)
#define Rep(i,l,r) for(int i=l;i<=r;i++)
using namespace std;

void read(int &v){
    char ch=getchar();int num=0;
    while(ch<'0'||ch>'9') ch=getchar();
    while(ch>='0'&&ch<='9') {
        num=num*10+ch-'0';
        ch=getchar();
    }
    v=num;
}

int n,k,l,r;
lld TOT,ans=inf,f[N];
int A[N];
struct queues{
    int id;lld v;
}q[N];

void init(){
    read(n);read(k);
    For(i,n) read(A[i]),TOT+=A[i];
}

void dp(){
    For(i,n){
        f[i]=A[i]+q[l].v;
        while(q[r].v>f[i]&&l<=r) r--;
        q[++r].v=f[i];q[r].id=i;
        while(q[l].id<i-k) l++;
    }
    Rep(i,n-k,n) ans=min(ans,f[i]);
    printf("%I64d",TOT-ans);
}

int main(){
    freopen("mowlawn.in","r",stdin);
    freopen("mowlawn.out","w",stdout);
    init();
    dp();
    return 0;
}
T1

 堆版本的，应老师要求写的= =

#include<set>
#include<map>
#include<cstdio>
#include<cstdlib>
#include<cstring>
#include<iostream>
#include<algorithm>
using namespace std;
const int N = 100010;
typedef long long lld;
typedef pair<lld,int> point;
#define w first
#define id second
#define For(i,n) for(int i=1;i<=n;i++)
#define Rep(i,l,r) for(int i=l;i<=r;i++)

point H[N];
lld ans,TOT;
int L,Loc[N],n,k,A[N];
lld dp[N];

//下调
void Down(int No,point H[]){
    int fa=No,son=No*2;
    while(son<=L){
        if(H[son].w>H[son+1].w&&son<L) {
            //swap(Loc[H[son].id],Loc[H[son+1].id]);
            son++;
        }
        if(H[son].w<H[fa].w) {
            swap(Loc[H[son].id],Loc[H[fa].id]);
            point c=H[son];H[son]=H[fa];H[fa]=c;
        }
        fa=son;son=fa*2;
    }
}
//删除堆元素
void Delete(int No,point H[]){
    Loc[H[L].id]=Loc[H[No].id];
    H[No]=H[L--];
    Down(No,H);
}

//上调 
void Up(int No,point H[]){
    int fa=L/2,son=L;
    while(H[son].w<H[fa].w&&son>1){
        swap(Loc[H[son].id],Loc[H[fa].id]);
        point c=H[son];H[son]=H[fa];H[fa]=c;
        son=fa;fa=son/2;
    }
}

void Insert(point NODE,point H[]){
    H[++L]=NODE;
    Loc[NODE.id]=L;
    Up(L,H);
}

void init(){
    scanf("%d%d",&n,&k);
    For(i,n) scanf("%d",&A[i]),TOT+=A[i];
}

void DP(){
    ans=1e18;
    Insert(make_pair(0,0),H);
    For(i,n){
        dp[i]=H[1].w+A[i];
        Insert(make_pair(dp[i],i),H);
        if(i>k)  Delete(Loc[i-k-1],H);
    }
    For(i,n) cout<<dp[i]<<endl;
    Rep(i,n-k,n) ans=(dp[i]<ans)?(dp[i]):(ans);
    printf("%I64d\n",TOT-ans);
}

int main(){
    freopen("mowlawn.in","r",stdin);
    freopen("mowlawn.out","w",stdout);
    init();
    DP();
    return 0;
}

 

T2: 很坑爹的bfs，考场上没看到是一些传送门。。就写了一个传送门的。。。由于增量是1，所以可以不用bfs

 1 #include<set>
 2 #include<map>
 3 #include<cstdio>
 4 #include<cstdlib>
 5 #include<cstring>
 6 #include<iostream>
 7 #include<algorithm>
 8 using namespace std;
 9 const int N = 310;
10 const int dx[5]={0,-1,1,0,0},
11           dy[5]={0,0,0,-1,1};
12 typedef pair<pair<int,int>,int>  newp;
13 #define x first
14 #define y second
15 #define For(i,n) for(int i=1;i<=n;i++)
16 #define Rep(i,l,r) for(int i=l;i<=r;i++)
17 char maze[N][N];
18 int x,y,n,m;bool hash[N][N];
19 newp q[N*3*N];
20 pair<int,int> two[3],cnt[30][2];
21 
22 void init(){
23     scanf("%d%d",&n,&m);
24     For(i,n) {
25         scanf("%s",maze[i]+1);
26         For(j,m){
27             if(maze[i][j]=='@'){x=i;y=j;}
28             if(isupper(maze[i][j])) 
29                 if(cnt[maze[i][j]-'A'+1][0].first>0)   cnt[maze[i][j]-'A'+1][1]=make_pair(i,j);
30                 else                                   cnt[maze[i][j]-'A'+1][0]=make_pair(i,j);
31         }
32     }
33 }
34 
35 int BFS(){
36     int l=0,r=1;q[r]=make_pair(make_pair(x,y),0);hash[x][y]=true;
37     while(l<r){
38         newp head=q[++l];
39         pair<int,int> First=head.x;int w=head.y;
40         if(maze[First.x][First.y]=='=') return w;
41         For(i,4){
42             int tx=First.x+dx[i],ty=First.y+dy[i];
43             if(tx>n||ty>m||tx<=0||ty<=0) continue;
44             if(!hash[tx][ty]&&maze[tx][ty]!='#'){
45                 hash[tx][ty]=true;
46                 if(isupper(maze[tx][ty])){
47                       if(cnt[maze[tx][ty]-'A'+1][0]!=make_pair(tx,ty)){
48                           q[++r]=make_pair(cnt[maze[tx][ty]-'A'+1][0],w+1);
49                           hash[tx][ty]=false;
50                       }
51                       else{
52                           q[++r]=make_pair(cnt[maze[tx][ty]-'A'+1][1],w+1);
53                           hash[tx][ty]=false;
54                       }
55                     continue;
56                 }
57                 q[++r]=make_pair(make_pair(tx,ty),w+1);
58             }
59         }
60     }
61 }
62 
63 int main(){
64     freopen("cornmaze.in","r",stdin);
65     freopen("cornmaze.out","w",stdout);
66     init();
67     printf("%d\n",BFS());
68     return 0;
69 }
T2

 

posted @ 2014-10-22 21:16  ZJDx1998  阅读(463)  评论(0)  编辑  收藏  举报