题目链接：https://codeforces.com/contest/1200/problem/B
ＷＡ了八发。。。
思路：在保证能跳到下一个砖块的前提下，包里的砖块数最大，防止需要砖块时不够的情况。每一种情况都得考虑到：
1 #include <iostream> 2 #include <cstring> 3 #include <cstdio> 4 #include <queue> 5 #include <algorithm> 6 #include <cmath> 7 #include <map> 8 #define mem(a,b) memset(a,b,sizeof(a)); 9 using namespace std; 10 #define INF 0x3f3f3f3f 11 typedef long long ll; 12 int dir[4][2] = {0,1,0,-1,1,0,-1,0}; 13 const int maxn = 100005; 14 int main() 15 { 16 int t,n,m,k; 17 ll a[105]; 18 cin >> t; 19 while(t--) 20 { 21 bool flag = 0; 22 cin >> n >> m >> k; 23 mem(a,0); 24 for(int i =1; i <= n; i++) 25 cin >> a[i]; 26 for(int i = 1; i < n; i++) 27 { 28 ll d,ne; 29 if(a[i+1] > a[i]) 30 { 31 d = a[i+1] - a[i]; 32 if(k >= a[i+1]) 33 { 34 m += a[i]; 35 } 36 else 37 { 38 if(d > k) 39 { 40 ne = a[i+1] - k - a[i]; 41 // cout << "ne = " << ne << "m = " << m << " a[i] = " << a[i] << " a[i+1] = " << a[i+1] <<endl; 42 if(m < ne) 43 { 44 flag = 1; 45 break; 46 } 47 else 48 { 49 m -= ne; 50 } 51 } 52 53 else 54 { 55 ne = a[i] - (a[i+1] - k); 56 m += ne; 57 } 58 } 59 } 60 else 61 { 62 d = a[i] - a[i+1]; 63 if(k <= a[i+1]) 64 { 65 ne = a[i] - (a[i+1] - k); 66 m += ne; 67 } 68 else 69 { 70 ne = a[i] ; 71 m += ne; 72 } 73 } 74 75 } 76 77 if(flag == 1) 78 cout << "NO" <<endl; 79 else 80 cout << "YES" << endl; 81 } 82 return 0; 83 }