背包九讲之完全背包，恰好装满，一维（滚动）数组

complete_pack-2.cpp

/*
 * 背包九讲之完全背包 恰好装满 滚动数组
 *  from: http://acm.hdu.edu.cn/showproblem.php?pid=1114
 * reference: https://blog.csdn.net/liujc_/article/details/44003167
 */

#include <bits/stdc++.h>

#define PMAX 1000000001

using namespace std;

/*
 * d[i] = min{ d[i], d[i-V[j]] + W[j] }
 */
int piggy_bank(int P[], int W[], int n, int V) {
    int *d = new int[V+1];
    int w;

    for (int i = 0; i <= V; i++) {
        if (i == 0)
            d[i] = 0;
        else
            d[i] = PMAX;
    }

    for (int i = 0; i < n; i++) {
        for (int j = 1; j <= V; j++) {
            if (j >= W[i]) {
                w = d[j-W[i]] + P[i];
                d[j] = d[j] < w ? d[j] : w;
            } else {
                d[j] = d[j];
            }
        }
    }

    w = d[V];
    delete d;

    return w;
}

int main() {
    int T;

    cin >> T;

    while (T--) {
        int E, F, N, d;
        int *P, *W;

        cin >> E >> F;
        cin >> N;

        P = new int[N];
        W = new int[N];

        for (int i = 0; i < N; i++)
            cin >> P[i] >> W[i];

        d = piggy_bank(P, W, N, F-E);
        if (d != PMAX)
            cout << "The minimum amount of money in the piggy-bank is " << d << "." << endl;
        else
            cout << "This is impossible." << endl;
    }

    return 0;
}