cp/codeforces/1003/c.cc
2025-04-26 14:16:04 -04:00

102 lines
1.8 KiB
C++

// {{{
#include <bits/stdc++.h>
// https://codeforces.com/blog/entry/96344
#pragma GCC optimize("O2,unroll-loops")
#pragma GCC target("avx2,bmi,bmi2,lzcnt,popcnt")
using namespace std;
template <typename T>
constexpr T MIN = std::numeric_limits<T>::min();
template <typename T>
constexpr T MAX = std::numeric_limits<T>::max();
template <typename T>
[[nodiscard]] static T sc(auto&& x) {
return static_cast<T>(x);
}
template <typename T>
[[nodiscard]] static T sz(auto&& x) {
return static_cast<T>(x.size());
}
template <typename... Args>
void pr(std::format_string<Args...> fmt, Args&&... args) {
std::print(fmt, std::forward<Args>(args)...);
}
template <typename... Args>
void pr(std::format_string<Args...> fmt) {
std::print(fmt);
}
template <typename... Args>
void prln(std::format_string<Args...> fmt, Args&&... args) {
std::println(fmt, std::forward<Args>(args)...);
}
template <typename... Args>
void prln(std::format_string<Args...> fmt) {
std::println(fmt);
}
void prln() {
std::println();
}
void prln(auto const& t) {
std::println("{}", t);
}
using ll = long long;
using ld = long double;
template <typename T>
using vec = std::vector<T>;
#define ff first
#define ss second
#define eb emplace_back
#define pb push_back
#define all(x) (x).begin(), (x).end()
#define rall(x) (x).rbegin(), (x).rend()
// }}}
void solve() {
int n, m;
cin >> n >> m;
vec<int> a(n);
for (auto& e : a)
cin >> e;
int x;
cin >> x;
a[0] = min(a[0], x - a[0]);
for (int i = 1; i < n; ++i) {
if (x - a[i] >= a[i - 1]) {
a[i] = min(a[i], x - a[i]);
} else if (a[i] < a[i - 1]) {
prln("NO");
return;
}
}
prln("YES");
}
// {{{
int main() {
cin.tie(nullptr)->sync_with_stdio(false);
int t = 1;
cin >> t;
while (t--) {
solve();
}
return 0;
}
// }}}