看了数据范围,想想这不暴力可以过??
DP #include<algorithm>
#include<iostream>
#include<cstdlib>
#include<cstring>
#include<cstdio>
#include<cmath>
using namespace std;
#define MAXN 10010
int n,m;
int ans;
int f[MAXN];
int a[MAXN],x[MAXN],y[MAXN];
int main()
{
scanf("%d%d",&n,&m);
for (int i=1;i<=m;i++)
{
scanf("%d%d%d",&a[i],&x[i],&y[i]);
f[i]=1;
for (int j=i-1;j>=1;j--)
{
if (f[j]+1<=f[i])
continue;
if (abs(x[i]-x[j])+abs(y[i]-y[j])<=a[i]-a[j])
if (f[i]<f[j]+1)
f[i]=f[j]+1;
ans=max(ans,f[i]);
}
}
printf("%d",ans=0 ? 1 : ans);
return 0;
}