1.AcWing 1057 股票交易4

#include<bits/stdc++.h>
#pragma GCC optimize(2)
#define ll long long
#define rep(i,a,n) for(int i=a;i<=n;i++)
#define per(i,n,a) for(int i=n;i>=a;i--)
#define endl '\n'
#define eps 0.000000001
#define pb push_back
#define mem(a,b) memset(a,b,sizeof(a))
#define IO ios::sync_with_stdio(false);cin.tie(0);
using
 
 namespace std;
const int INF=0x3f3f3f3f;
const ll inf=0x3f3f3f3f3f3f3f3f;
const int mod=1e9+7;
const int maxn=110+5;
int a[maxn],dp[maxn][maxn][2];
int main(){
    int n,m;cin>>n>>m;
    rep(i,1,n) cin>>a[i];
    mem(dp,-INF);
    rep(i,0,n) dp[i][0][0]=0; 
    rep(i,1,n){
        rep(j,
 
1,m){
            dp[i][j][0]=max(dp[i-1][j][0],dp[i-1][j][1]+a[i]);
            dp[i][j][1]=max(dp[i-1][j][1],dp[i-1][j-1][0]-a[i]);
        }
    }
    int ans=0;
    rep(i,1,m){
        ans=max(ans,dp[n][i][0]);
    }
    cout<<ans<<endl;
}

2.AcWing 1058股票交易5

#include<bits/stdc++.h>
#pragma
 
 GCC optimize(2)
#define ll long long
#define rep(i,a,n) for(int i=a;i<=n;i++)
#define per(i,n,a) for(int i=n;i>=a;i--)
#define endl '\n'
#define eps 0.000000001
#define pb push_back
#define mem(a,b) memset(a,b,sizeof(a))
#define IO ios::sync_with_stdio(false);cin.tie(0);
using namespace std;
const int INF=0x3f3f3f3f;
const ll inf=0x3f3f3f3f3f3f3f3f;
const int mod=1e9+7;
const int maxn=1e5+5;
int w[maxn],dp[maxn][3];
int main(){
    int n;scanf("%d",&n);
    rep(i,1,n) scanf("%d",&w[i]);
    rep(i,0,n+2) dp[i][0]=dp[i][1]=-INF;
    rep(i,1,n){
        dp[i][2]=max(dp[i-1][1],dp[i-1][2]);
        dp[i][1]=dp[i-1][0]+w[i];
        dp[i][0]=max(dp[i-1][0],dp[i-1][2]-w[i]);
    }     
    printf("%d\n",max(dp[n][1],dp[n][2]));
}