C :

#include <stdio.h>
 
void main(){
    int n,c = 0;
    scanf("%d",&n);
    int a[n];
    //读入元素
    int i,j;
    for(i = 0;i < n;i++){
        scanf("%d",&a[i]);
    } 
     
    //从每个数后面找比这个数小的数 
    for(i = 0;i < n - 1;i++){
        //循环a[i]后面的数 
        for(j = i + 1;j < n;j++){
            if(a[j] < a[i]){
                c++;
            } 
        }
    }
     
    printf("%d\n",c);
}

C++ :

#include <iostream>

using namespace std;

int main(){
	int n,i,j,a[20000],s=0;
	cin>>n;
	for(i=0;i<n;i++){
		cin>>a[i];
	}
	for(i=0;i<n;i++){
		for(j=i+1;j<n;j++){
			if(a[j]<a[i]){
				s++;
			}
		}
	}
	cout<<s<<endl;
}

Python :

n=int(input())
a=[]
for i in range(n):
    a.append(int(input()))
js=0
for i in range(n):
    for j in range(i+1,n):
        if(a[j]<a[i]):
            js=js+1
print(js)