stl大法好

不会map的可以看这篇文章

#include <iostream>
#include<algorithm>
#include<map> 
using namespace std;
int n,a[1000005],b[1000005],mn=9999999,mx=-9999999;
int main() {
    map<int,int> c;
    cin >> n;

    for (int i = 0; i < n; i++) {
        cin>>a[i];
    }
    for (int i = 0; i < n; i++) {
		cin>>b[i];
        mx=max(a[i]-b[i],mx);
        mn=min(a[i]-b[i],mn);
        c[a[i]-b[i]]++;
    }
    for(int i=mn;i<=mx;i++){
        if(c[i]>0) cout<<i<<' '<<c[i]<<endl;
    }

    return 0;
}