51nod1086 背包问题 V2

原题链接：https://www.51nod.com/onlineJudge/questionCode.html#!problemId=1086

思路：多重背包，二进制分解思路

AC代码：

#include<stdio.h>
#include<math.h>
#include<string.h>
#include<algorithm>
const int MAXN = 1e2 + 5;
const int MOD = 1e9 + 7;
typedef long long LL;
const double PI = acos(-1.0);
const double E = exp(1.0);
using namespace std;

int wi[MAXN], pi[MAXN], ci[MAXN], dp[50005];

void zore_pack(int cost, int value, int n) {
	for (int i = n; i >= cost; i--) {
		dp[i] = max(dp[i], dp[i - cost] + value);
	}
}

void compete_pack(int cost, int value, int n) {
	for (int i = cost; i <= n; i++) {
		dp[i] = max(dp[i], dp[i - cost] + value);
	}
}

int multiple_pack(int n, int w) {
	for (int i = 0; i < n; i++) {
		if (ci[i] * wi[i] > w) {
			compete_pack(wi[i], pi[i], w);
		}
		else {
			int k = 1;
			while (k < ci[i]) {
				zore_pack(k*wi[i], k*pi[i], w);
				ci[i] -= k;
				k <<= 1;
			}
			zore_pack(ci[i] * wi[i], ci[i] * pi[i], w);
		}
	}
	return dp[w];
}
int main() {
	int n, w;
	scanf("%d %d", &n, &w);
	for (int i = 0; i < n; i++) {
		scanf("%d %d %d", &wi[i], &pi[i], &ci[i]);
	}
	printf("%d\n", multiple_pack(n, w));
	return 0;
}