1)
3
1 2 0
2 3 1
3 4 0
1
2 3 -100

>2 1 2 0 3 4 0

2)
3
1 2 -100
2 3 1
3 4 -100
1
2 3 -100

>2 1 2 -100 3 4 -100

here are some tests... Last line is the correct answer

5  10 20 0  30 40 0  50 60 0  70 80 0  90 100 0
6  -30000 10 0  20 30 0  40 50 0  60 70 0  80 90 0  100 30000 0
5  10 20 0  30 40 0  50 60 0  70 80 0  90 100 0

5 -1000 1000 123  1001 2000 124  2001 3000 125  3001 4000 126  4001 5000 127
1 -30000 30000 100
0

1 -32000 32000 123
3 -1000 1000 100  2000 3000 0  4000 5000 -99
4 -32000 -1000 123 1000 2000 123 3000 4000 123 5000 32000 123

1 -32000 32000 123
1 -1000 1000 100
2 -32000 -1000 123 1000 32000 123

Yes, thanks!