i = 0 while i < N and ... i += 1
M = X[0] for k in range(1,N): if ... : M = X[k]
M = 0 for k in range(1,N): if X[k] > X[M]: ...
X[a] = 4 X[b] = 6 ...
nR = -1 for k in range(N): if X[k] == R: ... break;
for k in range(...): c = X[k] X[k] = X[N-1-k] X[N-1-k] = c
c = X[N-1] k = N-1 while k > 0: ... k -= 1 X[0] = c
B = [] c = 0 for x in A: if x < 0: ...