編程演算法 - 籬笆修理(Fence Repair) 代碼(C)

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籬笆修理(Fence Repair) 代碼(C)

本文地址: http://blog.csdn.net/caroline_wendy

題目: 把一塊木板切成N塊, 每次切兩塊, 切割的開銷是木板長度, 求將木板切割完的最小開銷.

即霍夫曼編碼(Huffman).

貪心演算法, 類似二叉樹型結構, 最短板和次短板是兄弟結點, 選取兩個最小木板, 最後進行切割, 合并兩個最小木板, 依次遞推.

代碼:

/* * main.cpp * *  Created on: 2014.7.17 *      Author: spike *//*eclipse cdt, gcc 4.8.1*/#include <stdio.h>#include <limits.h>#include <utility>#include <queue>#include <algorithm>using namespace std;class Program {typedef long long ll;static const int MAX_N = 10000;int N=5, L[MAX_N]={1,2,3,4,5};public:void solve() {ll ans = 0;while (N>1) {int mii1 = 0, mii2 = 1;if (L[mii1]>L[mii2]) swap(mii1, mii2);for (int i=2; i<N; ++i) {if (L[i]<L[mii1]) {mii2 = mii1;mii1 = i;} else if (L[i]<L[mii2]) {mii2 = i;}}int t = L[mii1]+L[mii2];ans += t;if (mii1 == N-1) swap(mii1, mii2);L[mii1] = t;L[mii2] = L[N-1];N--;}printf("result = %lld\n", ans);}};int main(void){Program P;P.solve();    return 0;}

輸出:

result = 33