getPartitionInt.py

def getPartitionInt( alist ):
    
    low  = 0
    high = len(alist)-1
    pos  = len(alist)

    while low <= high:
        mid = (low+high)/2

        if alist[mid] < 0:
            low = mid + 1
        elif alist[mid] >= 0 and mid < pos:
            high = mid - 1
            pos  = mid
        elif alist[mid] >= 0:
            high = mid - 1

    if pos == 0 or pos == len(alist):
        return -1
    else:
        return mid