hdu 1074 Doing Homework(状态压缩DP)

题意：学生要完成各科作业, 给出各科老师给出交作业的期限和学生完成该科所需时间, 如果逾期一天则扣掉一单位学分, 要你求出完成所有作业而被扣最小的学分, 并将完成作业的顺序输出.

#include<algorithm>
#include<iostream>
#include<limits.h>
#include<stdlib.h>
#include<string.h>
#include<cstring>
#include<iomanip>
#include<stdio.h>
#include<bitset>
#include<cctype>
#include<math.h>
#include<string>
#include<time.h>
#include<vector>
#include<cmath>
#include<queue>
#include<stack>
#include<list>
#include<map>
#include<set>

#define LL long long

using namespace std;
const LL mod = 1000000007;
const double PI = acos(-1.0);
const int INF = 99999999;
const int M = 1005;

struct node{
    string name;
    int time;
    int date;
}a[16];

struct DP{
    int time;
    int last;
    int pos;
    int score;
}dp[1 << 15 + 10];

int main()
{
    int t;
    int n;
    cin >> t;
    while( t-- ){
        cin >> n;
        for(int i = 0; i < n; ++i)
            cin >> a[i].name >> a[i].date >> a[i].time;
        int bit = 1 << n;
        int temp, past, redu;
        for(int i = 1; i < bit; ++i){
            dp[i].score = INF;
            for(int j = n - 1; j >= 0; --j){
                temp = 1 << j;
                if(!(i & temp)) continue;
                past = i - temp;
                redu = dp[past].time + a[j].time - a[j].date;
                redu = max(redu,0);
                if(redu + dp[past].score < dp[i].score){
                    dp[i].score = redu + dp[past].score;
                    dp[i].pos = j;
                    dp[i].last = past;
                    dp[i].time = dp[past].time + a[j].time;
                }
            }
        }
        stack<int> st;
        redu = bit - 1;
        while(redu)
        {
            st.push(dp[redu].pos);
            redu = dp[redu].last;
        }
        cout << dp[bit - 1].score << endl;
        while(!st.empty())
        {
            int top = st.top();
            cout << a[top].name << endl;
            st.pop();
        }
    }
    return 0;
}