题目：

#include
     
      #include
      
       #include
       
        #include
        
         #define db double#define ll long longusing namespace std;const int N=1e6+5;int n,d[N],p[N],C[N];ll s[N],c[N],dp[N];int q[N],he,tl;int rdn(){  int ret=0;bool fx=1;char ch=getchar();  while(ch>'9'||ch<'0'){
   if(ch=='-')fx=0;ch=getchar();}  while(ch>='0'&&ch<='9') ret=(ret<<3)+(ret<<1)+ch-'0',ch=getchar();  return fx?ret:-ret;}ll Y(int a){
   return dp[a]+c[a]*d[a]-s[a];}db slp(int u,int v){
   return (db)(Y(v)-Y(u))/(d[v]-d[u]);}int main(){  n=rdn();  for(int i=1;i<=n;i++)    d[i]=rdn(),p[i]=rdn(),C[i]=rdn();  for(int i=1;i<=n;i++)    d[i]=d[n]-d[i];  for(int i=n;i>=0;i--)    c[i]+=c[i+1]+p[i],s[i]=s[i+1]+(ll)p[i]*d[i];  he=1;q[tl=1]=n;dp[n]=C[n];  for(int i=n-1;i>=0;i--)    {      while(he
         
          <=c[i+1])he++;      int j=q[he];      dp[i]=dp[j]+c[j]*d[j]-s[j]-c[i+1]*d[j]+s[i+1]+C[i];      while(he
          
           =slp(q[tl-1],i))tl--; q[++tl]=i; } printf("%lld\n",dp[0]); return 0;}