hdoj薛猫猫杯程序设计网络赛1003 球球大作战

思路：

二分，check函数不是很好写。

实现：

1.

 #include <bits/stdc++.h>
 using namespace std;
 typedef long long ll;
 const ll INF = 0x3f3f3f3f3f3f3f3f;
 ll a[];
 int n, k;
 bool check(ll x)
 {
     int cnt = ;
     ll sum = ;
     for (int i = ; i <= n; i++)
     {
         if (a[i] >= x) continue;
         sum = a[i++];
         while (i <= n && sum < x)
         {
             sum += a[i++]; cnt++;
         }
         if (i > n && sum < x) cnt++;
         i--;
     }
     return cnt <= k;
 }
 int main()
 {
     int T;
     cin >> T;
     while (T--)
     {
         ll l = INF, r;
         cin >> n >> k;
         for (int i = ; i <= n; i++)
         {
             cin >> a[i];
             l = min(l, a[i]);
             r += a[i];
         }
         ll ans = l;
         while (l <= r)
         {
             ll m = l + r >> ;
             if (check(m))
             {
                 ans = m;
                 l = m + ;
             }
             else r = m - ;
         }
         cout << ans << endl;
     }
     return ;
 }

2.

 #include <bits/stdc++.h>
 using namespace std;
 typedef long long ll;
 const ll INF = 0x3f3f3f3f3f3f3f3f;
 ll a[], b[];
 int n, k;
 bool check(ll x)
 {
     for (int i = ; i <= n; i++) b[i] = a[i];
     int cnt = ;
     for (int i = ; i <= n; i++)
     {
         if (b[i] >= x) continue;
         b[i + ] += b[i];
         cnt++;
     }
     return cnt <= k;
 }
 int main()
 {
     int T;
     cin >> T;
     while (T--)
     {
         ll l = INF, r;
         cin >> n >> k;
         for (int i = ; i <= n; i++)
         {
             cin >> a[i];
             l = min(l, a[i]);
             r += a[i];
         }
         ll ans = l;
         while (l <= r)
         {
             ll m = l + r >> ;
             if (check(m))
             {
                 ans = m;
                 l = m + ;
             }
             else r = m - ;
         }
         cout << ans << endl;
     }
     return ;
 }