【Luogu】P3800点收集（DP）

　　题目链接

　　原题解

　　代码

#include<iostream>
#include<cstdio>
#include<cstring>
#include<cctype>
#include<cmath>
#include<algorithm>
using namespace std;

inline long long read(){
    long long num=,f=;
    char ch=getchar();
    while(!isdigit(ch)){
        if(ch=='-')    f=-;
        ch=getchar();
    }
    while(isdigit(ch)){
        num=num*+ch-'';
        ch=getchar();
    }
    return num*f;
}
int n,m,k,t;

int f[];
int ans;

struct Node{
    int x,y,val;
}que[];
bool cmp(Node a,Node b){    return a.x<b.x;    }

int main(){
    n=read(),m=read(),k=read(),t=read();
    for(int i=;i<=k;++i)    que[i]=(Node){read(),read(),read()};
    sort(que+,que+k+,cmp);
    for(int i=;i<=k;++i){
        f[i]=que[i].val;
        for(int j=;j<i;++j)
            if(abs(que[i].y-que[j].y)<=t*abs(que[j].x-que[i].x))
                f[i]=max(f[i],f[j]+que[i].val);
        ans=max(ans,f[i]);
    }
    printf("%d",ans);
    return ;
}