大佬帮忙看看c题思路是不是有问题

#include<bits/stdc++.h>
#define line printf("------\n")
#define endl "\n"
using namespace std;
typedef long long ll;
typedef pair<int, int> PII;
const int N = 1e6 + 10, M = 1e9 + 10;
int ix[4] = {1,-1,0,0}, iy[4] = {0,0,1,-1};
int a, b; 


int main(){
	ios::sync_with_stdio(false), cin.tie(0), cout.tie(0);
	int x, y;
	cin >> a;
	while(a --){
		cin >> x >> y;
		vector<int> v(x);
		int flag = 1;
		for(int i = 0; i < x; i++){
			cin >> v[i];
		}
		for(int i = 1; i < x; i++){
			if(v[i - 1] > v[i]){
				if(v[i - 1] - v[i] <= y) v[i] = v[i - 1]; 
				else {
					flag = 0;
					break;
				}
			} else {
				if(v[i] - v[i - 1] > y){
					v[i] -= y;
				} else {
					v[i] = v[i - 1];	
				}
			}	
		}
		
		cout << (flag ? "Yes" : "No") << endl;
	}

 
	return 0;
}