ZOJ 3812 We Need Medicine 01背包+位优化

题目链接：点击打开链接

#include <cstdio>
#include <algorithm>
#include <iostream>
#include <cstring>
#include <map>
typedef unsigned long long ll;
using namespace std;
const int N = 400 + 1;
const int M = 200000 + 1;
int t[N], w[N], g[51][M], ans[N], dep;
ll d[M];
map<ll, int> id;

char ch;
void get(int& z) {
	while ((ch = getchar()) > '9' || ch < '0');
	z = ch - '0';
	while ((ch = getchar()) >= '0' && ch <= '9')
		z = z * 10 + ch - '0';
}

int main() {
	for (ll i = 1; i <= 50; ++i)
		id[1ll << i] = i;

	int cas, n, m, x, y;
	ll v, mx = (1ll << 51) - 1;

	get(cas);
	while (cas -- > 0) {
		memset(d, 0, sizeof d);
		d[0] = 1;

		memset(g, -1, sizeof g);
		get(n); get(m);
		for (int i = 0; i < n; ++i) {
			get(w[i]); get(t[i]);
			for (int j = M - t[i] - 1; j >= 0; --j)
				if (d[j] > 0) {
					v = d[j + t[i]];
					d[j + t[i]] |= (d[j] << w[i]) & mx;
					v = v ^ d[j + t[i]];
					while (v > 0) {
						if (v & 1) {
							v = v & (v - 1);
							continue;
						}
						x = id[v & (v - 1) ^ v];
						g[x][j + t[i]] = i;

						v = v & (v - 1);
					}
				}
			//g[w[i]][t[i]] = i;
		}

		while (m -- > 0) {
			get(x); get(y);
			if (g[x][y] >= 0) {
				dep = 0;
				while (x > 0 && y > 0) {
					ans[dep++] = g[x][y];
					x -= w[ans[dep - 1]];
					y -= t[ans[dep - 1]];
				}
				for (int i = dep - 1; i >= 0; --i) {
					if (i == 0)
						printf("%d\n", ans[i] + 1);
					else
						printf("%d ", ans[i] + 1);
				}
			} else
				puts("No solution!");
		}
	}
	return 0;
}