自学C++新人，哪位大佬对我的代码提出点改进意见

#include <bits/stdc++.h>
using namespace std;
int main() {
double num,nw,od,oall,ogood,nall,ngood,npo,opo;
	cin>>num;
	int a[10086]={};
	cin>>oall>>ogood;
	opo=ogood/oall;
	for(int i=2;i<=num;i++)
	{
		cin>>nall>>ngood;
		npo=ngood/nall;
		if(npo-opo>0.05) a[i]=2;//cout<<"better";
		if(opo-npo>0.05) a[i]=0;//cout<<"worse";
		if(npo-opo<0.05&&opo-npo<0.05) a[i]=1;//cout<<"same";
	}
	for(int j=2;j<=num;j++)
	{
		if (a[j]==0) cout<<"worse"<<endl;
		if (a[j]==1) cout<<"same"<<endl;
		if (a[j]==2) cout<<"better"<<endl;
	}
    return 0;
}