单调队列优化dp（捡垃圾的机器人）

/*************************************************************************
    > File Name: a.cpp
    > Author: QWX
    > Mail: 
    > Created Time: 2018/10/16 16:47:07
 ************************************************************************/


//{{{ #include
#include<iostream>
#include<cstdio>
#include<algorithm>
#include<vector>
#include<cmath>
#include<queue>
#include<map>
#include<set>
#include<cassert>
#include<string>
#include<cstring>
#include<complex>
//#include<bits/stdc++.h>
#define vi vector<int>
#define pii pair<int,int>
#define mp make_pair
#define pb push_back
#define first fi
#define second se
#define pw(x) (1ll << (x))
#define sz(x) ((int)(x).size())
#define all(x) (x).begin(),(x).end()
#define rep(i,l,r) for(int i=(l);i<(r);i++)
#define per(i,r,l) for(int i=(r);i>=(l);i--)
#define FOR(i,l,r) for(int i=(l);i<=(r);i++)
#define cl(a,b) memset(a,b,sizeof(a))
#define fastio ios::sync_with_stdio(false);cin.tie(0);
#define lson l , mid , ls
#define rson mid + 1 , r , rs
#define INF 0x3f3f3f3f
#define LINF 0x3f3f3f3f3f3f3f3f
#define ll long long
#define ull unsigned long long
#define dd(x) cout << #x << " = " << (x) << "," 
#define de(x) cout << #x << " = " << (x) << "\n" 
#define endl "\n"
using namespace std;
//}}}

const int N=1e5+7;
int dp[N],dist[N],dist_0[N],x[N],y[N],w[N],sw[N],que[N];
int n,C;

inline int f(int j)
{
    return dp[j-1]-dist[j]+dist_0[j];
}


int solve()
{
    cin>>C>>n;
    int h=1,t=0;
    cl(dp,0);
    FOR(i,1,n){
        cin>>x[i]>>y[i]>>w[i];
        sw[i]=sw[i-1]+w[i];
        dist[i]=dist[i-1]+(abs(x[i]-x[i-1])+abs(y[i]-y[i-1]));
        dist_0[i]=abs(x[i])+abs(y[i]);
        while(h<=t&&f(i)<f(que[t]))t--;
        que[++t] = i;    
        while(h<=t&&sw[i]-sw[que[h]-1]>C)h++;
        dp[i]=f(que[h])+dist[i]+dist_0[i];
    }
}

int main()
{
    int T;cin>>T;
    while(T--){
        solve();
        cout<<dp[n]<<endl;
        if(T)cout<<endl;
    }
    return 0;
}    
/*
    1
    10
    4
    1 2 3
    1 0 3
    3 1 4
    3 1 4
*/