TopCoder Problems

topcoder_q.py

# Solution of Level 1 ZigZag Problem. (http://community.topcoder.com/stat?c=problem_statement&pm=1259&rd=4493)
def zigzag(a):
    if len(a) <= 1: return 1
    
    result = 1
    prev_diff = 0
    for i in range(len(a)-1):
        diff = a[i+1] - a[i]
        if diff == 0:
            continue
        
        if (prev_diff >= 0 and diff < 0) or (prev_diff <= 0 and diff > 0):
            result += 1
            prev_diff = diff
                
    return result