算法竞赛入门经典 分金币

算法竞赛入门经典 分金币

/*Name: 分金币 Copyright: 刘汝佳 Author: Analyst Date: 28/02/14 00:31Description: dev-cpp 5.5.3*/#include <iostream>#include <algorithm>using namespace std;const int maxn = 1000000+10;long long A[maxn], C[maxn], tot, M;int main(){int n;while (scanf("%d", &n) == 1)        //输入数据大，scanf()比cin快 {tot = 0;for (int i = 1; i <= n; ++i){scanf ("%lld", &A[i]);      //%lld输入long long tot += A[i];}M = tot / n;C[0] = 0;for (int i = 1; i < n; ++i)C[i] = C[i-1] + A[i] - M;   //递推C数组 sort(C, C+n);long long x1 = C[n/2], ans = 0; //x1中位数 for (int i = 0; i < n; ++i)     //转手金币数 ans += abs(x1-C[i]);printf("%lld\n",ans); }return 0;} 

ps：

主要用数轴上的无数点到某个点的最短距离来抽象化。（引入：中位数概念）

同时需要理解递推公式：

for (int i = 1; i < n; ++i)
C[i] = C[i-1] + A[i] - M;   //递推C数组