Pro.ID22115 TitleDelivering Food Title链接http://10.20.2.8/oj/exercise/problem?problem_id=22115 AC0 Submit0 Ratio- 时间&空间限制描述College students have wide freedom in many circumstances. For instance, nowadays, more and more students choose to order food from outside school, instead of eating in the school canteens. Owing to the rapid development of network communication, the ways students ordering food are multifarious. They can order food on the phone, as well as through network such as QQ or BBS. Ordering food is convenient and laborsaving, however, sometimes many students may complain about waiting too long time for the food and some students may even eat other food instead because of not being able to wait so long. As a result, the students who receive food late will be depressed and the benefit and credit of the fast food canteens will be debased.
Ivan and Cristy graduated from the same college recently. Considering the awful circumstances above, they establish a delivery company (named IC), which controls the food delivery of the fast food canteens. They hope the IC Company provides students with good and fast services in scientific, rational and concentrative ways of delivery. Certainly, they hope to benefit at the same time.
Now, let’s suppose there are N places, one of which is the unique food delivery center and all the food are sent from it. The other N-1 places are dorms to which food must be delivered. Each dorm has a time limit after which food can not be accepted, that is to say, the food ordered by the students in a dorm must be received before the dorm’s time limit. Because the IC Company adopts scientific and concentrative methods, all the food needed are well prepared and there is no limit in the amount of food that can be delivered at a time. However, because the company has been set up only for a short time, there is only one delivery team at work for the moment. In addition, in order to estimate the efficiency of delivery, the IC Company will compute the time for delivery. They set the time when the food is just sent from the delivery center 0, and the distance between two places is denoted as the walking time between them. Because there may be more than one way connecting two places, the time need to walk from one place to another place may be not unique.
Now, your job is to help the IC Company to find out a delivery way, which will satisfy all the requests of the dorms (arrive at every dorm before the dorm’s time limit) and minimize the total waiting time of all the dorms (the waiting time of a dorm is from 0 to the time the food is accepted by the students in the dorm). If there is no way satisfying all the requests of the dorms, the IC Company will regard the delivery as a failure. 输入Input will contain several test cases. Each test case begins with a line containing an integer n ( 2 <= n <= 30 ), representing the number of places, and we suppose the first place is the delivery center. In the following n lines, each line represents one place and contains n positive integers (include 0) separated by a single space. The j-th integer of the i-th line is the walking time from the i-th place to the j-th place. The next line after the n lines contains n-1 positive integer, representing the time limits of the dorms.
The last test case is followed by a line containing one zero. No extra spaces at the beginning/end of each line. 输出Description College students have wide freedom in many circumstances. For instance, nowadays, more and more students choose to order food from outside school, instead of eating in the school canteens. Owing to the rapid development of network communication, the ways students ordering food are multifarious. They can order food on the phone, as well as through network such as QQ or BBS. Ordering food is convenient and laborsaving, however, sometimes many students may complain about waiting too long time for the food and some students may even eat other food instead because of not being able to wait so long. As a result, the students who receive food late will be depressed and the benefit and credit of the fast food canteens will be debased.
Ivan and Cristy graduated from the same college recently. Considering the awful circumstances above, they establish a delivery company (named IC), which controls the food delivery of the fast food canteens. They hope the IC Company provides students with good and fast services in scientific, rational and concentrative ways of delivery. Certainly, they hope to benefit at the same time.
Now, let’s suppose there are N places, one of which is the unique food delivery center and all the food are sent from it. The other N-1 places are dorms to which food must be delivered. Each dorm has a time limit after which food can not be accepted, that is to say, the food ordered by the students in a dorm must be received before the dorm’s time limit. Because the IC Company adopts scientific and concentrative methods, all the food needed are well prepared and there is no limit in the amount of food that can be delivered at a time. However, because the company has been set up only for a short time, there is only one delivery team at work for the moment. In addition, in order to estimate the efficiency of delivery, the IC Company will compute the time for delivery. They set the time when the food is just sent from the delivery center 0, and the distance between two places is denoted as the walking time between them. Because there may be more than one way connecting two places, the time need to walk from one place to another place may be not unique.
Now, your job is to help the IC Company to find out a delivery way, which will satisfy all the requests of the dorms (arrive at every dorm before the dorm’s time limit) and minimize the total waiting time of all the dorms (the waiting time of a dorm is from 0 to the time the food is accepted by the students in the dorm). If there is no way satisfying all the requests of the dorms, the IC Company will regard the delivery as a failure. Input Input will contain several test cases. Each test case begins with a line containing an integer n ( 2 <= n <= 30 ), representing the number of places, and we suppose the first place is the delivery center. In the following n lines, each line represents one place and contains n positive integers (include 0) separated by a single space. The j-th integer of the i-th line is the walking time from the i-th place to the j-th place. The next line after the n lines contains n-1 positive integer, representing the time limits of the dorms.
The last test case is followed by a line containing one zero. No extra spaces at the beginning/end of each line. Output For each test case in the input you should output an integer, representing the minimum total waiting time of all the dorms. If no solution is found, you should output -1 in the corresponding line. Sample Input 4
0 3 8 6
4 0 7 4
7 5 0 2
6 9 3 0
30 8 30
3
0 10 10
10 0 1
10 1 0
10 10
0 Sample Output 36
-1 Source 样例输入4
0 3 8 6
4 0 7 4
7 5 0 2
6 9 3 0
30 8 30
3
0 10 10
10 0 1
10 1 0
10 10
0 样例输出36
-1 作者 |
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