Codility Genomic Range Query

Question

I recently discovered Codility and I'm going on with the demo training. I wrote this solution to the Genomic Range Query problem, it works fine, solution is provided with dynamic programming, but it scores only 87% instead of 100% as expected.

Anyone has any idea?

Here you can find the problem, it is in the Prefix section. Just start a test to see the problem description! Codility training

Thank you!

def solution(S, P, Q):
    # write your code in Python 2.6
    S = list(S)
    sol = [[0]*len(S),[0]*len(S),[0]*len(S),[0]*len(S)]

    mapping = {"A":1, "C":2, "G":3, "T":4}

    for i in range(0,len(S)):
        if S[i] == 'A':
            sol[0][i]+= 1

        elif S[i] == 'C':
            sol[1][i] += 1

        elif S[i] == 'G':
            sol[2][i] += 1

        elif S[i] == 'T':
            sol[3][i] += 1

        if i < len(S)-1:
            sol[0][i+1] = sol[0][i]
            sol[1][i+1] = sol[1][i]
            sol[2][i+1] = sol[2][i]
            sol[3][i+1] = sol[3][i]

    for n in range(0, len(P)):

            l = P[n]
            r = Q[n]
            pre_sum = [0,0,0,0]
            if l > 0:
                pre_sum = [sol[0][l],sol[1][l],sol[2][l],sol[3][l]]
            post_sum = [sol[0][r],sol[1][r],sol[2][r],sol[3][r]]
            if post_sum[0]-pre_sum[0] > 0:
                P[n] = 1
            elif post_sum[1]-pre_sum[1] > 0:
                P[n] = 2
            elif post_sum[2]-pre_sum[2] > 0:
                P[n] = 3
            elif post_sum[3]-pre_sum[3] > 0:
                P[n] = 4
            else:
                P[n] = mapping[S[P[n]]];

    return P


pass

Answer 1

This works 100/100 too

def solution(S, P, Q):
    res = []
    for i in range(len(P)):
        if 'A' in S[P[i]:Q[i]+1]:
            res.append(1)
        elif 'C' in S[P[i]:Q[i]+1]:
            res.append(2)
        elif 'G' in S[P[i]:Q[i]+1]:
            res.append(3)
        else:
            res.append(4)
    return res