http://codeforces.com/problemset/problem/651/B Beautiful Paintings

实际上就是给n个数形成多个递增的链，如果是相等的数自然不放在一起，因为这样是无法贡献值的。

#include <iostream>
#include <string>
#include <cstdio>
#include <algorithm>
#include <vector>
#include <stack>
#include <queue>
#define MAX 1005
#define mod 998244353ll
#define INF 0x3f3f3f3f
#define ll long long
using namespace std;
int a[1005];
int main() {
    freopen("a.txt", "r", stdin);
    freopen("b.txt", "w", stdout);
    int n, x;
    cin >> n;
    for (int i = 1; i <= n; ++i) {
        scanf("%d", &x);
        a[x]++;
    }
    int ans = 0;
    while (n) {
        int c = 0;
        for (int i = 1; i <= 1000; ++i) {
            if (a[i]) {
                n--;
                a[i]--;
                c++;
            }
        }
        ans = ans + c - 1;
    }
    cout << ans << endl;
    return 0;
}