UVa11400 Lighting System Design

参考了这个 点击打开链接才会的题

刚开始写动归思维转不过来，中间的推理和证明没什么感觉。

#include <iostream>
#include <algorithm>
using namespace std;

const int MAXN = 1000 + 5;

struct info {
	int V;
	int K;
	int C;
	int L;
};

info plan[MAXN];
int quantity[MAXN] = { 0 };//灯泡数量累计
int total_cost[MAXN] = { 0 };

//从小到大排序意味着每次替换都必须购买voltage
bool compare(info& a, info& b) {
	return a.V <= b.V;
}

void quantity_ini(int n) {
	quantity[0] = plan[0].L;
	for (int i = 1; i < n; i++)
		quantity[i] = quantity[i - 1] + plan[i].L;
}

int redesign(info a[], int n) {
	quantity_ini(n);
//	bool adopted[MAXN] = { 0 };//标记已经选用的voltage
	for (int i = 0; i < n; i++) {
		total_cost[i] = a[i].K + a[i].C*quantity[i];
		for (int j = 1; j < i; j++) {//全i（即j = 0）的情况已经考虑过了
			int temp = total_cost[j] + (quantity[i] - quantity[j])*a[i].C + a[i].K;
			if (total_cost[i] > temp)
				total_cost[i] = temp;
		}
	}
	return 0;
}

int main() {
	int n;
	while (cin >> n && n != 0) {
		for (int i = 0; i < n; i++)
			cin >> plan[i].V >> plan[i].K >> plan[i].C >> plan[i].L;
		sort(plan, plan + n, compare);
		redesign(plan, n);
		cout << total_cost[n-1] << endl;
	}
	return 0;
}