Java Reference
In-Depth Information
The method performs a primary sort on rows and a secondary sort on columns.
For example, the following array
{{
4
,
2
},{
1
,
7
},{
4
,
5
},{
1
,
2
},{
1
,
1
},{
4
,
1
}}
will be sorted to
{{
1
,
1
},{
1
,
2
},{
1
,
7
},{
4
,
1
},{
4
,
2
},{
4
,
5
}}.
***7.17
(
Financial tsunami
) Banks lend money to each other. In tough economic times, if
a bank goes bankrupt, it may not be able to pay back the loan. A bank's total assets
are its current balance plus its loans to other banks. The diagram in Figure 7.8
shows five banks. The banks' current balances are 25, 125, 175, 75, and 181 mil-
lion dollars, respectively. The directed edge from node 1 to node 2 indicates that
bank 1 lends 40 million dollars to bank 2.
125
1
100.5
85
25
75
0
3
125
40
125
320.5
75
125
2
175
4
181
F
IGURE
7.8
Banks lend money to each other.
If a bank's total assets are under a certain limit, the bank is unsafe. The money it
borrowed cannot be returned to the lender, and the lender cannot count the loan
in its total assets. Consequently, the lender may also be unsafe, if its total assets
are under the limit. Write a program to find all the unsafe banks. Your program
reads the input as follows. It first reads two integers
n
and
limit
, where
n
indi-
cates the number of banks and
limit
is the minimum total assets for keeping a
bank safe. It then reads
n
lines that describe the information for
n
banks with IDs
from
0
to
n-1
.
The first number in the line is the bank's balance, the second number indicates
the number of banks that borrowed money from the bank, and the rest are pairs
of two numbers. Each pair describes a borrower. The first number in the pair is
the borrower's ID and the second is the amount borrowed. For example, the
input for the five banks in Figure 7.8 is as follows (note that the limit is 201):
5 201
25 2 1 100.5 4 320.5
125 2 2 40 3 85
175 2 0 125 3 75
75 1 0 125
181 1 2 125
The total assets of bank 3 are which is under 201, so bank 3 is
unsafe. After bank 3 becomes unsafe, the total assets of bank 1 fall below
Thus, bank 1 is also unsafe. The output of the program should be
(75
+
125),
(125
+
40).
Unsafe banks are 3 1
