HDU 4970 killing monsters

In the beginning, I thought it was a line segment tree. I thought it could be too complicated... But this question seems to be stuck in the line segment tree...

Specific Practices:

For each tower, record attack [l] + = D, attack [R + 1]-= D; for each block, the attack is caused by the prefix and attack [1] + attack [2] +... + attack [I];

Traverse from the back to the front to calculate the total damage from the current point to the end;

 

PS: It seems that many people write data in a tree array... I still don't know what the relationship is with the tree array... Orz

 

 1 #include <iostream> 2 #include <cstring> 3 #include <cstdio> 4 using namespace std; 5  6 const int maxn = 100005 ; 7  8 long long attack[maxn]; 9 long long sum[maxn];10 11 int main (){12     int n,m,l,r,d,k,x,ans;13     long long h;14     while (~scanf ("%d",&n)&&n){15         memset (attack,0,sizeof attack);16         scanf ("%d",&m);17         while (m--){18             scanf ("%d%d%d",&l,&r,&d);19             attack[l]+=d;20             attack[r+1]-=d;21         }22         long long temp=0;23         for (int i=1;i<=n;i++){24             temp+=attack[i];25             attack[i]=temp;26         }27         temp=0;28         for (int i=n;i>=1;i--){29             temp+=attack[i];30             sum[i]=temp;31         }32         scanf ("%d",&k);33         ans=0;34         while (k--){35             scanf ("%I64d%d",&h,&x);36             if (sum[x]