想问问若用结构体中某一关键字进行二分，具体的重载函数该应该怎么写，或者说有更简单的方法，求解答

#include<bits/stdc++.h>
typedef long long ll;
using namespace std;
template<typename T> void re(T&x){x = 0; int sign = 1; char c;do{c = getchar(); if (c == '-') sign = -1;}while(!isdigit(c)); do{x = x * 10 + c - '0'; c = getchar();}while(isdigit(c)); x *= sign;}
void write(int x){if (x < 0) x = -x, putchar('-'); if (x < 10) putchar(x + '0'); else write(x / 10), putchar(x % 10 + '0');}

const int N = 4e5 + 1000;

struct node{
	int x, val;
	bool operator < (const node &p) const {
		return p.x < x;
	}
};

vector<node> alls;

int n, sum[N], a[N], b[N];

bool cmp(node a, node b){
	return a.x < b.x;
}

int main(){
	re(n);
	for (int i = 1; i <= n; i ++) re(a[i]);
	for (int i = 1; i <= n; i ++) re(b[i]), sum[i] = sum[i - 1] + b[i];
	for (int i = 1; i <= n; i ++) alls.push_back((node){a[i], sum[i]});
	sort(alls.begin(), alls.end(), cmp);
	int q, x, y;
	re(q);
	while (q --){
		re(x), re(y);
		node *it1 = lower_bound(alls.begin(), alls.end(), x);
		node *it2 = upper_bound(alls.begin(), alls.end(), y);
	}
	return 0;
}

以上是错误代码，还是求问结构体重载写法