QUICK SOLUTIONS:

Problem A:
sample: 17.525 s
limit: 55 s
 8d19:20:50  02a1.cpp OK  17.296 s
 3d08:53:07  03a2.cpp OK  22.866 s
24d22:16:12  12a1.cpp OK   6.650 s

Problem D:
sample: 24.828 s
limit: 75 s
 3d00:57:53  02d2.cpp OK  35.335 s
 9d21:51:39  04d1.cpp OK  10.573 s

Problem E:
sample: 0.36 s
limit: 1.2 s
22d16:56:23  02e2.cpp OK   1.194 s

Problem H:
sample: 52.764 s
limit: 160 s
24d22:20:13  12h1.cpp OK   0.140
21d09:46:20  01h1.c   OK   0.357
18d01:55:53  02h3.cpp OK   0.449
29d16:17:53  04h2.cpp OK  26.741