【CQ18高一暑假前挑战赛5】标程

【A：暴力】

#include<bits/stdc++.h>
using namespace std;
const int maxn=;
int a[maxn],vis[maxn],N,M;
int main()
{
    scanf("%d%d",&N,&M);
    for(int i=;i<=M;i++){
        scanf("%d",&a[i]);
        vis[a[i]]=;
    }
    for(int i=;i<=N;i++)
      if(!vis[i]) printf("%d\n",i);
    return ;
}

【B：模拟】

#include<bits/stdc++.h>
using namespace std;
const int maxn=;
vector<short int>G[maxn];
int main()
{
    int N,M,x,i,j;
    scanf("%d%d",&N,&M);
    for(i=;i<=N;i++)
      for(j=;j<M;j++){
        scanf("%d",&x); G[i].push_back(x);
    }
    printf("%d %d\n",M,N);
    for(i=;i<M;i++){
       for(j=;j<=N;j++) printf("%d ",G[j][i]);
       printf("\n");
    }
    return ;
}

【C：数位DP入门题】

#include<bits/stdc++.h>
using namespace std;
#define ll long long
const int maxn=;
int N,L,a[maxn];
ll dp[maxn][][maxn],num[maxn][][maxn],ans;
void divede()
{
    while(N){ a[++L]=N%; N/=; }
}
ll dfs(int pos,int lim,int x)
{
    if(pos==){  num[pos][lim][x]=; return x==;}
    if(!lim&&dp[pos][lim][x]) return dp[pos][lim][x];
    int ups=lim?a[pos]:;
    for(int i=;i<=ups;i++){
        dp[pos][lim][x]+=(dfs(pos-,lim&(i==ups),i))+(x==?num[pos-][lim&(i==ups)][i]:);
        num[pos][lim][x]+=num[pos-][lim&(i==ups)][i];
    }
    return dp[pos][lim][x];
}
int main()
{
    scanf("%d",&N);
    divede();
    for(int i=;i<=a[L];i++) ans+=dfs(L-,i==a[L],i);
    printf("%lld\n",ans);
    return ;
}

【D：单调队列】

#include<bits/stdc++.h>
using namespace std;
typedef long long ll;
const int maxn=;
const int inf=1e9+;
int a[maxn],L1[maxn],b[maxn],R1[maxn],L2[maxn],R2[maxn],q[maxn],head;
vector<int>G[maxn];
ll get(int u)
{
    int Len=G[b[u]].size(); ll res=;
    for(int i=;i<Len;i++){
        if(u>=G[b[u]][i]){
            ll r=min(R1[G[b[u]][i]],R2[u])-u+;
            ll l=G[b[u]][i]-max(L2[u],L1[G[b[u]][i]])+;
            if(r>&&l>) res+=l*r;
        }
        else {
            ll r=min(R2[u],R1[G[b[u]][i]])-G[b[u]][i]+;
            ll l=u-max(L2[u],L1[G[b[u]][i]])+;
            if(r>&&l>) res+=l*r;
        }
    }
    return res;
}
int main()
{
    int N,i; ll ans=;
    scanf("%d",&N);
    for(i=;i<=N;i++) scanf("%d",&a[i]);
    for(i=;i<=N;i++) scanf("%d",&b[i]);
    a[]=inf; head=; q[head]=;
     for(i=;i<=N;i++){ //若有相同，只算左边第一个。
         while(head&&a[i]>a[q[head]]) head--;
         L1[i]=q[head]+; q[++head]=i;
    }
    a[N+]=inf; head=; q[head]=N+;
    for(i=N;i>=;i--){
        while(head&&a[i]>=a[q[head]]) head--;
        R1[i]=q[head]-; q[++head]=i;
    }
    for(i=;i<=N;i++) G[a[i]].push_back(i);

    b[]=inf; head=; q[head]=;
     for(i=;i<=N;i++){
         while(head&&b[i]>b[q[head]]) head--;
         L2[i]=q[head]+; q[++head]=i;
    }
    b[N+]=inf; head=; q[head]=N+;
    for(i=N;i>=;i--){
        while(head&&b[i]>=b[q[head]]) head--;
        R2[i]=q[head]-; q[++head]=i;
    }
    for(i=;i<=N;i++) ans+=get(i);
    printf("%lld\n",ans);
    return ;
}