洛谷 P1031 [NOIP 2002 提高组] 均分纸牌

很明显的贪心题

EaCode：

#include<iostream>
#include<algorithm>
using namespace std;
int a[110];
int main(){
	int N, avg = 0, ans = 0;
	cin >> N;
	for(int i = 1; i <= N; i++){
		cin >> a[i];
		avg += a[i];
	}
	avg /= N;
	for(int i = 1; i <= N; i++){
		if(a[i] > avg){
			int x = a[i] - avg, l = i - 1, r = i + 1, pos = 0;
			while(x && l >= 1){
				if(a[l] < avg){
					int c = avg - a[l];
					if(c >= x){
						x = 0;
						a[l] += x;
						a[i] -= x;
					}else{
						x -= c;
						a[l] += c;
						a[i] -= c;
					}
					pos = l;
				}
				l--;
			}
			if(pos){
				//cout << pos << endl;
				ans += i - pos;
			}
			pos = 0;
			while(x && r <= N){
				//cout << "d";
				if(a[r] < avg){
					int c = avg - a[r];
					if(c >= x){
						x = 0;
						a[r] += x;
						a[i] -= x;
					}else{
						x -= c;
						a[r] += c;
						a[i] -= c;
					}
					pos = r;
				}
				r++;
			}
			if(pos){
				//cout << pos << endl;
				ans += pos - i;
			}
		}
	}
	cout << ans;
	return 0;
} 

交上去就拿了20分，还是不够贪。。
然后换思路，从左往右，如果小于平均值，从下一个拿，如果大于平均值，给下一个。

AcCode：

#include<iostream>
using namespace std;

int main() {
    int N, sum = 0, ans = 0;
    cin >> N;
    int a[N+1];
    
    for(int i = 1; i <= N; i++) {
        cin >> a[i];
        sum += a[i];
    }
    
    int average = sum / N;
    
    for(int i = 1; i <= N; i++) {
        if(a[i] != average) {
            ans++;
            a[i+1] += a[i] - average;
        }
    }
    
    cout << ans;
    return 0;
}