題目：戳這裡

題意：機器人走過一個花，可以給那個花澆水，給定步數下，問花的最小的最大能量值。

學習部落格：戳這裡

本人程式碼：

 1 #include <bits/stdc++.h>
 2 typedef long long ll;
 3 const int maxn = 1e6+10;
 4 const ll inf = 1e18;
 5 using namespace std;
 6 ll a[maxn];
 7 ll b[maxn];
 8 ll m, n;
 9 int check(ll mid) {
10     for(ll i = 1; i <= n+1ll; ++i) {
 
11         b[i] = 0;
12     }
13     for(ll i = 1; i <= n; ++i) {
14         ll temp = mid/a[i];
15         if(mid%a[i]) ++temp;//所有的數必須大於等於mid
16         if(i == n && b[i] >= temp) break;//當走到n，要考慮是不是還需要往下走了
17         b[i]++;
18         if(b[i] < temp) {
19             b[i+1] += temp - b[i];
 
20             b[i] = temp;
21         }
22     }
23     ll cnt = 0;
24     for(ll i = 1; i <= n+1ll; ++i) {
25         cnt += b[i];
26         if(cnt > m) return 0;
27     }
28     return 1;
29 
30 }
31 int main(){
32     int t;
33     scanf("%d", &t);
34     while(t--) {
35         scanf("%lld %lld
 
", &n, &m);
36         for(ll i = 1; i <= n; ++i) {
37             scanf("%lld", a+i);
38         }
39         ll l = 1, r = inf;
40         ll ans = 0ll;
41         while(l <= r) {
42             ll mid = (l + r) / 2ll;
43             if(check(mid)) l = mid + 1ll, ans = mid;
44             else r = mid - 1ll;
45         }
46         printf("%lld\n", ans);
47     }
48 
49     return 0;
50 }