Problem e Sending email Time Limit: 3 seconds A new internet watchdog is creating a stir in ringfield. Mr: X, if that is his real name, has come up with a sensational scoop. There are n SMTP servers connected by network cables. Each of the m cables connects two computers and has a certain latency measured in milliseconds required to send an email message What is the shortest time required to send a message from server s to server t along a sequence of cables? Assume that there is no delay incurred at any of the servers. Input The first line of input gives the number of cases, N.n test cases follow. Each one starts with a line containing n(2<=n<20000),m(0<=m<50000) S(O<=S<n)and T(0<=T<n. S!=T. The next m lines will each contain 3 integers: 2 different servers (in the range [0, n-l) that are connected by a bidirectional cable and the latency, w, along this cable (0<=W<=10000 Output For each test case, output the line"Case #x: followed by the number of milliseconds required to send a message from s to T. Print"unreachable f there is no route froms to t Sample Input Sample output Case#1:100 2101 Case#2:150 011 Case #3: unreachable 3320 01100 02200 1250 20019 Problem E Sending email Time Limit: 3 seconds "A new internet watchdog is creating a stir in Springfield. Mr. X, if that is his real name, has come up with a sensational scoop." Kent Brockman There are n SMTP servers connected by network cables. Each of the m cables connects two computers and has a certain latency measured in milliseconds required to send an email message. What is the shortest time required to send a message from server S to server T along a sequence of cables? Assume that there is no delay incurred at any of the servers. Input The first line of input gives the number of cases, N. N test cases follow. Each one starts with a line containing n (2<=n<20000), m (0<=m<50000), S (0<=S<n) and T (0<=T<n). S!=T. The next m lines will each contain 3 integers: 2 different servers (in the range [0, n-1]) that are connected by a bidirectional cable and the latency, w, along this cable (0<=w<=10000). Output For each test case, output the line "Case #x:" followed by the number of milliseconds required to send a message from S to T. Print "unreachable" if there is no route from S to T. Sample Input Sample Output 3 2 1 0 1 0 1 100 3 3 2 0 0 1 100 0 2 200 1 2 50 2 0 0 1 Case #1: 100 Case #2: 150 Case #3: unreachable