find largest number

find_largest.py

def find_largest(L):
    N = len(L)
    minL = [ [None] * N for j in range(N)]
    sumL = [ [None] * N for j in range(N)]

    def helper(i):
        if i==0:
            minL[0][0] = L[0]
        else:
            for j in range(i):
                minL[j][i] = min(minL[j][i-1], L[i])
            minL[i][i] = L[i]
        if i+1<N:
            helper(i+1)
    
    helper(0)

    def helper2(i):
        if i==0:
            sumL[0][0] = L[0]
        else:
            for j in range(i):
                sumL[j][i] = sumL[j][i-1] + L[i]
            sumL[i][i] = L[i]
        if i+1<N:
            helper2(i+1)
    
    helper2(0)

    curM = 0
    for i in range(N):
        for j in range(i,N):
            curM = max(curM, minL[i][j] * sumL[i][j])
    
    return curM