HDU 1257 最少攔截系統

貪心， 從前面往後讀取，對於每一個高度，都要用之前一個系統最接近的高度來消滅，這樣才最省。

#include <iostream>
#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <string>
#include <algorithm>
#include <fstream>
#include <set>
#include <map>
#include <queue>
#include <stack>
#include <list>
#include <vector>
#include <cmath>
#include <iomanip>
#include <cmath>
typedef long long LL;
typedef unsigned long long LLU;
const double PI=acos(-1.0);
using namespace std;
#define MAXN 100000+10
#define INF 1 << 30
int main (){
    int n;
    while(scanf("%d",&n) != EOF){
        int a[MAXN] = {0};
        for(int i = 1; i <= n; i++)
            scanf("%d",&a[i]);
        int maxh[MAXN];
        int ans = 1;
        for(int i = 1; i <= n; i++){
            for(int j = 1; j <= ans; j++){
                if(a[i] <= maxh[j]){
                    maxh[j] = a[i];
                    break;
                }
                if(a[i] > maxh[j] && j == ans){
                    maxh[++ans] = a[i];
                    break;
                }
            }
        }
        printf("%d\n",ans-1);
    }
    return 0;
}