p3.in

5
3
360 480
420 540
600 660
3
0 1440
1 3
2 4
5
99 150
1 100
100 301
2 5
150 250
2
0 720
720 1440
4
2 4
3 5
0 2
4 6

p3.py

#!/usr/bin/env python

def assign_to(new_schedule, list_schedule):
    new_start, new_end = new_schedule
    result = None
    if len(list_schedule):
        for (i, v) in enumerate(list_schedule):
            old_start, old_end = v
            if len(list_schedule) == 1 and new_end <= old_start:
                result = [new_schedule] + list_schedule
            elif i == len(list_schedule) - 1 and new_start >= old_end:
                result = list_schedule + [new_schedule]
            elif new_start >= old_end and new_end <= list_schedule[i+1][0]:
                result = list_schedule[:i - 1] + [new_schedule] + list_schedule[i:]
            else:
                continue
    else:
        result = [new_schedule]
    return result

def main():
    test_num = int(input())
    for c_no in range(test_num):
        schedule_num = int(input())
        c = []
        j = []
        result = ""
        failed = False
        for _ in range(schedule_num):
            v = input().split(" ")
            if not failed:
                new_min, new_max = v
                insert_data = [int(new_min), int(new_max)]

                _j = assign_to(insert_data, j)
                if _j != None:
                    j = _j
                    result += "J"
                else:
                    _c = assign_to(insert_data, c)
                    if _c != None:
                        result +="C"
                        c = _c
                    else:
                        result = "IMPOSSIBLE"
                        failed =True
                        # break
        print("Case #%s: %s\n" % (c_no+1, result))
        
if __name__ == "__main__":
    main()