def LCS(S1, S2, x, y): if x == 0 or y == 0: return 0 if S1[x - 1] == S2[y - 1]: return LCS(S1, S2, x - 1, y - 1) + 1 return max(LCS(S1, S2, x, y - 1), LCS(S1, S2, x - 1, y)) S1 = "QEREW" S2 = "QWRE" x = len(S1) y = len(S2) pr...