Educational Codeforces Round 52 Editorial C

模拟，前缀和

#include<algorithm>
#include<cstdio>
#include<cmath>
#include<iostream>
#include<cstring>
#include<set>
#include<map>
#include<iterator>
#include<queue>
#include<vector>
#include<string>
using namespace std;

typedef long long ll;
const int N=1e6+10;
const long long INF=1e18;
const double eps=0.0000001;
int a[N],s[N];
char b[100][100];
const int maxn = 1e6 + 10;
const int inf = 0x3f3f3f3f;

ll n, k, h[maxn], cnt[maxn];

int main() {
    while(~scanf("%lld%lld", &n, &k)) {
        memset(cnt, 0,sizeof(cnt));
        ll MIN = inf, MAX = 0;
        for(int i=1;i<=n;i++)
        {
            scanf("%lld", &h[i]);
            MIN = min(h[i], MIN);
            MAX = max(MAX, h[i]);
            cnt[h[i]]++;
        }
        ll ans = 0, sum = 0;
        for(int i=MAX;i>=MIN + 1;i--)
        {
            cnt[i] += cnt[i + 1];//统计每层的砖块数
            if(sum + cnt[i] > k)//不大于k的砖块数合并消去
            {
                ans++;
                sum = cnt[i];
            } else {
                sum += cnt[i];
            }
        }
        printf("%lld\n", ans + (sum > 0));
    }
    return 0;
}