双向链表
1 #include <bits/stdc++.h>
2 using namespace std;
3
4 const int maxn=100000+15;
5 int pre[maxn],nex[maxn];
6 bool boo[maxn];
7 int n,m;
8 int main()
9 {
10 scanf("%d",&n);
11 for (int i=1;i<=n;i++) pre[i]=nex[i]=0;
12 for (int i=2;i<=n;i++)
13 {
14 int k,p;
15 scanf("%d%d",&k,&p);
16 if (p==0)
17 {
18 pre[i]=pre[k];
19 nex[i]=k;
20 pre[k]=i;
21 nex[pre[i]]=i;
22 }
23 else
24 {
25 nex[i]=nex[k];
26 pre[i]=k;
27 nex[k]=i;
28 pre[nex[i]]=i;
29 }
30 }
31 scanf("%d",&m);
32 for (int i=1;i<=m;i++)
33 {
34 int x;
35 scanf("%d",&x);
36 if (boo[x]) continue;
37 boo[x]=true;
38 n--;
39 pre[nex[x]]=pre[x];
40 nex[pre[x]]=nex[x];
41 }
42 int now=0;
43 for (int i=1;i<=n;i++)
44 {
45 now=nex[now];
46 if (i<n) printf("%d ",now);
47 else printf("%d
",now);
48 }
49 return 0;
50 }
1 #include<cstdio>
2 #include<cstring>
3 #define MAXN 100005
4 using namespace std;
5 int n;
6 bool vis[MAXN];
7 struct queue{
8 int l,r,no;
9 }q[MAXN];
10 int main(){
11 scanf("%d",&n);
12 q[1]=(queue){0,0,1};
13 for(int i=2;i<=n;i++){
14 int k,p;scanf("%d%d",&k,&p);
15 if(p==0){
16 q[i].l=q[k].l;q[i].r=k;
17 q[q[i].l].r=i;
18 q[q[i].r].l=i;
19 }
20 else {
21 q[i].l=k;q[i].r=q[k].r;
22 q[q[i].l].r=i;
23 q[q[i].r].l=i;
24 }
25 q[i].no=i;
26 }
27 int m;scanf("%d",&m);
28 memset(vis,0,sizeof(vis));
29 while(m--){
30 int x;scanf("%d",&x);
31 if(vis[x]) continue;
32 q[q[x].l].r=q[x].r;
33 q[q[x].r].l=q[x].l;
34 vis[x]=true;
35 }
36 int now=q[0].r;
37 while(now){
38 printf("%d ",q[now].no);
39 now=q[now].r;
40 }
41 return 0;
42 }
View Code优先队列
1 #include <queue>
2 #include <cstdio>
3 #include <cstdlib>
4 #include <algorithm>
5 #include <cmath>
6 using namespace std;
7
8 const int maxn=10000+15;
9 int n,m;
10 int a[maxn],b[maxn],c[maxn];
11 struct Node
12 {
13 int key,x,y;
14 Node(int key=0,int x=0,int y=0):key(key),x(x),y(y) {}
15 };
16 const bool operator < (const Node &a,const Node &b)
17 {
18 return a.key>b.key;
19 }
20 priority_queue <Node> que;
21 int f(int x,int y)
22 {
23 return a[x]*y*y+b[x]*y+c[x];
24 }
25 int main()
26 {
27 scanf("%d%d",&n,&m);
28 for (int i=1;i<=n;i++) scanf("%d%d%d",&a[i],&b[i],&c[i]);
29 for (int i=1;i<=n;i++) que.push(Node(f(i,1),i,1));
30 for (int i=1;i<=m;i++)
31 {
32 Node now=que.top();
33 if (i<m) printf("%d ",now.key);
34 else printf("%d
",now.key);
35 que.pop();
36 que.push(Node(f(now.x,now.y+1),now.x,now.y+1));
37 }
38 return 0;
39 }
并查集
1 #include <bits/stdc++.h>
2 using namespace std;
3
4 const int maxn=200000+15;
5 int rank[maxn],fa[maxn],n,tot;
6 map <int ,int > Map;
7 int found(int x)
8 {
9 if (fa[x]==x) return x;
10 return fa[x]=found(fa[x]);
11 }
12 int merge(int x,int y)
13 {
14 int fx=found(x),fy=found(y);
15 if (fx==fy) return 0;
16 if (rank[fx]==rank[fy]) rank[fx]++;
17 if (rank[fx]>rank[fy]) fa[fy]=fx;
18 else fa[fx]=fy;
19 return 0;
20 }
21 int xx[maxn],yy[maxn],sg;
22 int main()
23 {
24 int G;
25 scanf("%d",&G);
26 while (G--)
27 {
28 scanf("%d",&n);
29 Map.clear();
30 tot=0;
31 sg=0;
32 for (int i=1;i<=n;i++)
33 {
34 int a,b,c;
35 scanf("%d%d%d",&a,&b,&c);
36 if (Map.find(a)==Map.end())
37 {
38 tot++;
39 Map[a]=tot;
40 rank[tot]=0;
41 fa[tot]=tot;
42 }
43 if (Map.find(b)==Map.end())
44 {
45 tot++;
46 Map[b]=tot;
47 rank[tot]=0;
48 fa[tot]=tot;
49 }
50 a=Map[a];
51 b=Map[b];
52 if (c==1)
53 {
54 merge(a,b);
55 }
56 else
57 {
58 sg++;
59 xx[sg]=a;
60 yy[sg]=b;
61 }
62 }
63 bool boo=true;
64 for (int i=1;i<=sg;i++)
65 if (found(xx[i])==found(yy[i])) boo=false;
66 if (boo) printf("YES
");
67 else printf("NO
");
68 }
69 return 0;
70 }
RMQ
1 #include <bits/stdc++.h>
2 using namespace std;
3
4 const int maxn=100000+15;
5 int f[20][maxn],n,m;
6 int main()
7 {
8 scanf("%d",&n);
9 for (int i=1;i<=n;i++) scanf("%d",&f[0][i]);
10 int w=(int)(log(n)/log(2));
11 for (int i=1;i<=w;i++)
12 for (int j=1;j<=n-(1 << i)+1;j++)
13 f[i][j]=max(f[i-1][j],f[i-1][j+(1 << (i-1))]);
14 scanf("%d",&m);
15 while (m--)
16 {
17 int x,y;
18 scanf("%d%d",&x,&y);
19 int w=(int)(log(y-x+1)/log(2));
20 printf("%d
",max(f[w][x],f[w][y-(1 << w)+1]));
21 }
22 return 0;
23 }
树状数组
1 int lowbit(int x){
2 return x&-x;
3 }
4 int change(int x,int y){
5 for (;x<=n;x+=lowbit(x)) f[x]+=y;
6 return 0;
7 }
8 int ask(int x){
9 int ans=0;
10 for (;x;x-=lowbit(x)) ans+=f[x];
11 return ans;
12 }
1 #include<cstdio>
2 #include<iostream>
3 #define MAXN 200005
4 using namespace std;
5 int n,m;
6 int fa1[MAXN],fa2[MAXN];
7 inline int lowbit(int x){return x&-x;}
8 inline int add1(int x,int y){
9 for(;x<=n;x+=lowbit(x)) fa1[x]+=y;
10 return 0;
11 }
12 inline int add2(int x,int y){
13 for(;x<=n;x+=lowbit(x)) fa2[x]+=y;
14 return 0;
15 }
16 inline int ask1(int x){
17 int res=0;
18 for(;x;x-=lowbit(x)) res+=fa1[x];
19 return res;
20 }
21 inline int ask2(int x){
22 int res=0;
23 for(;x;x-=lowbit(x)) res+=fa2[x];
24 return res;
25 }
26 inline void add(int x,int y){add1(x,y);add2(x,x*y);}
27 inline void update(int l,int r,int x){add(l,x);add(r+1,-x);}
28 inline int sum(int x){return (x+1)*ask1(x)-ask2(x);}
29 inline int que(int l,int r){return sum(r)-sum(l-1);}
30 inline void fir(){
31 int l,r,w;scanf("%lld%lld%lld",&l,&r,&w);
32 update(l,r,w);
33 }
34 inline void sec(){
35 int l,r;scanf("%lld%lld",&l,&r);
36 int ans=que(l,r);
37 printf("%lld
",ans);
38 }
39 int main(){
40 scanf("%d%d",&n,&m);int a;
41 for(int i=1;i<=n;i++) scanf("%lld",&a),update(i,i,a);
42 while(m--){
43 char opt;cin>>opt;
44 if(opt=='A') fir();
45 if(opt=='Q') sec();
46 }
47 }
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