acwing学习记录

#include 
using namespace std;
int a[100010];
int root(int x)
{
if(x!=a[x])return  a[x]=root(a[x]);
return x;
}
void merge_root(int x,int y)
{int i=root(x),j=root(y);
if(i!=j)
    a[i]=root(a[j]);
}
int main()
{
    int n,m;
    cin>>n>>m;
    for(int i=0;i>g>>x>>y;
    if(g=='M')merge_root(x,y);
    else if(root(x)==root(y))cout<<"Yes"< 
单链表 
#include 

using namespace std;

const int N = 100010;
int head, e[N], ne[N], idx;
void init()
{
    head = -1;
    idx = 0;

void add_to_head(int x)
{
    e[idx] = x, ne[idx] = head, head = idx ++ ;
}
void add(int k, int x)
{
    e[idx] = x, ne[idx] = ne[k], ne[k] = idx ++ ;
}
void remove(int k)
{
    ne[k] = ne[ne[k]];
}

int main()
{
    int m;
    cin >> m;
    init();
    while (m -- )
    {
        int k, x;
        char op;
        cin >> op;
        if (op == 'H')
        {
            cin >> x;
            add_to_head(x);
        }
        else if (op == 'D')
        {
            cin >> k;
            if (!k) head = ne[head];
            else remove(k - 1);
        }
        else
        {
            cin >> k >> x;
            add(k - 1, x);
        }
    }
    for (int i = head; i != -1; i = ne[i]) cout << e[i] << ' ';
    cout << endl;
    return 0;
}

 
双链表 
#include 
using namespace std;
const int N = 100010;
int m;
int e[N], l[N], r[N], idx;
// 在节点a的右边插入一个数x
void insert(int a, int x)
{
    e[idx] = x;
    l[idx] = a, r[idx] = r[a];
    l[r[a]] = idx, r[a] = idx ++ ;
}
// 删除节点a
void remove(int a)
{
    l[r[a]] = l[a];
    r[l[a]] = r[a];
}
int main()
{
    cin >> m;
    // 0是左端点，1是右端点
    r[0] = 1, l[1] = 0;
    idx = 2;
    while (m -- )
    {
        string op;
        cin >> op;
        int k, x;
        if (op == "L")
        {
            cin >> x;
            insert(0, x);
        }
        else if (op == "R")
        {
            cin >> x;
            insert(l[1], x);
        }
        else if (op == "D")
        {
            cin >> k;
            remove(k + 1);
        }
        else if (op == "IL")
        {
            cin >> k >> x;
            insert(l[k + 1], x);
        }
        else
        {
            cin >> k >> x;
            insert(k + 1, x);
        }
    }
    for (int i = r[0]; i != 1; i = r[i]) cout << e[i] << ' ';
    cout << endl;
    return 0;
}

 
手写栈 
#include 
using namespace std;
int a[100010]={0};
int main()
{int T;
cin>>T;
int idex=0;
while(T--)
{
    string s;
    cin>>s;
    if(s=="push"){int x;
        scanf("%d",&x);
        a[++idex]=x;
    }
    if(s=="query")cout< 
队列 
#include 
using namespace std;
int a[100010]={0};
int main()
{int T;
cin>>T;
int idex=-1,h=-1;
while(T--)
{
    string s;
    cin>>s;
    if(s=="push"){int x;
        scanf("%d",&x);
        a[++idex]=x;
    }
    if(s=="query")cout<0?"NO":"YES")< 
单调栈 
#include 
using namespace std;
int a[100010]={0};
int main()
{
    stackstk;
    int n;
    cin>>n;
    while(n--)
    {int x;
        cin>>x;
    while(!stk.empty()&&stk.top()>=x)stk.pop();
    if(stk.empty())cout<<-1<<' ';
    else cout< 
单调队列 
#include
using namespace std;
const int N=1000010;
int a[N],q[N];
int main()
{int n,k,head=0,tail=-1;
cin>>n>>k;
for(int i=0;ia[i]&&head<=tail)tail--;
    q[++tail]=i;
   if (i >= k - 1) printf("%d ",a[q[head]]);
    }
cout<= k - 1) printf("%d ",a[q[head]]);
    }
    cout< 
KMP 
#include
using namespace std;
const int N=100010,M=1000010;
char p[N],s[M];
int ne[N],n,m;
int main()
{cin>>n>>p+1>>m>>s+1;
for(int i=2,j=0;i<=n;i++)
{
    while(j&&p[i]!=p[j+1])j=ne[j];
    if(p[i]==p[j+1])j++;
    ne[i]=j;
}
    for(int i=1,j=0;i<=m;i++)
{
    while(j&&s[i]!=p[j+1])j=ne[j];
    if(s[i]==p[j+1])j++;
    if(j==n)
    {
        printf("%d ",i-n);
        j=ne[j];
    }
}
}