import random
from bisect import bisect_left
from collections import Counter

def rand(start, F):
    return start + bisect_left(F, random.random())-1

def normalisedCumu(fs):
    tot = sum(fs)
    ret = [0]
    cumu = 0
    for v in fs:
        cumu += v
        ret.append(cumu/tot)
    return ret

### Test ###
#ps = [0, 0.3, 0.4, 1]
start = 70
F = normalisedCumu([1]*10 + [0]*3 + [1]*4)
simuN = 10000
d = Counter([rand(start, F) for _ in range(simuN)])
for k in sorted(d.keys()):
    print (k, ": ", float(d[k])/simuN)