k树状数组简单易懂的详解_FlushHip的博客-CSDN博客_树状数组
可以参考以上文章先行理解树状数组。
描述：
Farmer John's cows have discovered that the clover growing along the ridge of the hill (which we can think of as a one-dimensional number line) in his field is particularly good.
Farmer John has N cows (we number the cows from 1 to N). Each of Farmer John's N cows has a range of clover that she particularly likes (these ranges might overlap). The ranges are defined by a closed interval [S,E].
But some cows are strong and some are weak. Given two cows: cowi and cowj, their favourite clover range is [Si, Ei] and [Sj, Ej]. If Si <= Sj and Ej <= Ei and Ei - Si > Ej - Sj, we say that cowi is stronger than cowj.
For each cow, how many cows are stronger than her? Farmer John needs your help!
输入：
The input contains multiple test cases.
For each test case, the first line is an integer N (1 <= N <= 105), which is the number of cows. Then come N lines, the i-th of which contains two integers: S and E(0 <= S < E <= 105) specifying the start end location respectively of a range preferred by some cow. Locations are given as distance from the start of the ridge.
The end of the input contains a single 0.
输出：
For each test case, output one line containing n space-separated integers, the i-th of which specifying the number of cows that are stronger than cowi.
样例输入：
3 1 2 0 3 3 4 0
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样例输出：
1 0 0
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注释：
Huge input and output,scanf and printf is recommended.
#include<iostream>
#include<algorithm>
using namespace std;
int arr[500010];
int maxi=0;
int c[500010];
struct temp
{
int a,b,point;
bool operator <(const struct temp p)const
{
if(b==p.b)
{
return a<p.a;
}
else return b>p.b;
}
}ui[500010];
int lowbit(int n)
{
return n&(-n);
}
int getsum(int n)
{
int sum=0;
while(n>0)
{
sum+=c[n];
n-=lowbit(n);
}
return sum;
}
void Update(int n,int m)
{
while(n<=maxi)
{
c[n]+=m;
n+=lowbit(n);
}
return ;
}
int main()
{
int sum;
while(cin>>sum)
{
if(sum==0)break;
maxi=0;
memset(c,0,sizeof(c));
for(int n=1;n<=sum;n++)
{
cin>>ui[n].a>>ui[n].b;
ui[n].a++;
ui[n].b++;
ui[n].point=n;
maxi=max(maxi,ui[n].b);
}
sort(ui+1,ui+1+sum);
for(int n=1;n<=sum;n++)
{
Update(ui[n].a,1);
if(n==1)
arr[ui[n].point]=getsum(ui[n].a)-1;
else
{
if(ui[n].a==ui[n-1].a&&ui[n].b==ui[n-1].b){
arr[ui[n].point]=arr[ui[n-1].point];
}
else arr[ui[n].point]=getsum(ui[n].a)-1;
}
}
cout<<arr[1];
for(int n=2;n<=sum;n++)
{
cout<<" "<<arr[n];
}
cout<<endl;
}
return 0;
}
