for example
$ ./a.out "1" "0" "10"
root is 3051
<---- wait for signal
I'm 3051, left is 3052, right is 3053 | $ kill -USR1 3051
I'm 3052, left is 3056, right is 3057 |
I'm 3056 |
I'm 3057 |
I'm 3053, left is 3054, right is 3055 |
I'm 3054, left is 3058, right is 3059 |
I'm 3058 |
I'm 3059 |
I'm 3055 |
<---- wait for signal
I'm 3054, left is 3058, right is 3059 | $kill -USR1 3054
I'm 3058 |
I'm 3059
<---- wait for signal
I'm 3058 | $ kill -USR2 3056
I'm 3054, left is 3058, right is 3059 |
I'm 3053, left is 3054, right is 3055 |
I'm 3051, left is 3052, right is 3053 |