错误记录：

题目说输入在int范围内，但是运算过程中可能超int；后来开了很多longlong就过了

 #include<cstdio>

 #include<algorithm>

 #include<cstring>

 #include<vector>

 #include<map>

 using namespace std;

 #define fi first

 #define se second

 #define mp make_pair

 #define pb push_back

 typedef long long ll;

 typedef unsigned long long ull;

 typedef pair<int,int> pi;

 struct Q

 {

     ll x1,x2,y;int c,type;

 }q[];

 int nq;

 bool operator<(const Q &a,const Q &b)

 {

     return a.y<b.y||(a.y==b.y&&a.type<b.type);

 }

 int n,w,h;

 ll ans;

 namespace S

 {

 #define lc (num<<1)

 #define rc (num<<1|1)

 #define mid (l+((r-l)>>1))

 ll d[],addv[];

 void build(int l,int r,int num)

 {

     if(l==r)    {d[num]=addv[num]=;return;}

     build(l,mid,lc);build(mid+,r,rc);

     d[num]=addv[num]=;

 }

 int L,R;ll x;

 void pd(int l,int r,int num)

 {

     d[lc]+=addv[num];d[rc]+=addv[num];

     addv[lc]+=addv[num];addv[rc]+=addv[num];

     addv[num]=;

 }

 void _addx(int l,int r,int num)

 {

     if(L<=l&&r<=R)

     {

         d[num]+=x;addv[num]+=x;

         return;

     }

     pd(l,r,num);

     if(L<=mid)    _addx(l,mid,lc);

     if(mid<R)    _addx(mid+,r,rc);

     d[num]=max(d[lc],d[rc]);

 }

 ll _que(int l,int r,int num)

 {

     if(L<=l&&r<=R)    return d[num];

     pd(l,r,num);

     ll ans=;

     if(L<=mid)    ans=max(ans,_que(l,mid,lc));

     if(mid<R)    ans=max(ans,_que(mid+,r,rc));

     return ans;

 }

 #undef lc

 #undef rc

 #undef mid

 }

 map<ll,ll> ma;

 ll t0[];

 int main()

 {

     int i;ll a,b,c;

     while(scanf("%d%d%d",&n,&w,&h)==)

     {

         nq=;

         for(i=;i<=n;i++)

         {

             scanf("%lld%lld%lld",&a,&b,&c);

             q[++nq].y=a-w+;q[nq].x1=b-h+;q[nq].x2=b;q[nq].c=c;q[nq].type=;

             q[++nq].y=a+;q[nq].x1=b-h+;q[nq].x2=b;q[nq].c=c;q[nq].type=;

         }

         ans=;

         t0[]=;

         for(i=;i<=nq;i++)    t0[++t0[]]=q[i].x1,t0[++t0[]]=q[i].x2;

         sort(t0+,t0+t0[]+);t0[]=unique(t0+,t0+t0[]+)-t0-;

         ma.clear();

         for(i=;i<=t0[];i++)    ma[t0[i]]=i;

         for(i=;i<=nq;i++)    q[i].x1=ma[q[i].x1],q[i].x2=ma[q[i].x2];

         sort(q+,q+nq+);

         S::build(,t0[],);

         for(i=;i<=nq;i++)

         {

             if(q[i].type==)

             {

                 S::L=q[i].x1;S::R=q[i].x2;S::x=-q[i].c;

                 S::_addx(,t0[],);

             }

             else

             {

                 S::L=q[i].x1;S::R=q[i].x2;S::x=q[i].c;

                 S::_addx(,t0[],);

             }

             if(i==nq||q[i].y!=q[i+].y)

             {

                 S::L=;S::R=t0[];

                 ans=max(ans,S::_que(,t0[],));

             }

         }

         printf("%lld\n",ans);

     }

     return ;

 }