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Fix code indentation

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This commit is contained in:
Pragy Agarwal 2020-01-27 15:59:28 +05:30
parent 1eaa3c0de9
commit eb1c9f64af
1 changed files with 34 additions and 36 deletions
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70
Recursion and Backtracking/3.md
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@ -14,31 +14,31 @@ output: 2
```python ```python
def check(a, b): def check(a, b):
sq = int((a + b) ** 0.5) sq = int((a + b) ** 0.5)
return (sq * sq) == (a + b) return (sq * sq) == (a + b)
if len(A) == 1: # corner case if len(A) == 1: # corner case
return int(check(A[0], 0)) return int(check(A[0], 0))
count = 0 count = 0
def permute_distinct(S, i): def permute_distinct(S, i):
global count global count
if i == len(S): if i == len(S):
count += 1 count += 1
for j in range(i, len(S)): for j in range(i, len(S)):
if S[j] in S[i:j]: # prevent duplicates if S[j] in S[i:j]: # prevent duplicates
continue continue
if i > 0 and (not check(S[j], S[i-1])): # invalid solution - branch and bound if i > 0 and (not check(S[j], S[i-1])): # invalid solution - branch and bound
continue continue
S[i], S[j] = S[j], S[i] S[i], S[j] = S[j], S[i]
permute_distinct(S, i+1) permute_distinct(S, i+1)
S[i], S[j] = S[j], S[i] # backtrack S[i], S[j] = S[j], S[i] # backtrack
permute_distinct(A, 0) permute_distinct(A, 0)
return count return count
``` ```
Gray Code Gray Code
@ -67,11 +67,11 @@ Example G(2) to G(3):
``` ```
```python ```python
def gray(self, n): def gray(self, n):
codes = [0, 1] # length 1 codes = [0, 1] # length 1
for i in range(1, n): for i in range(1, n):
new_codes = [s | (1 << i) for s in reversed(codes)] new_codes = [s | (1 << i) for s in reversed(codes)]
codes += new_codes codes += new_codes
return codes return codes
``` ```
N Queens N Queens
@ -92,20 +92,18 @@ B = ["cat", "cats", "and", "sand", "dog"]
Output 1: Output 1:
["cat sand dog", "cats and dog"] ["cat sand dog", "cats and dog"]
```
```python ```python
def wordBreak(A, B): def wordBreak(A, B):
B = set(B) B = set(B)
sents = [] sents = []
def foo(i, start, sent): def foo(i, start, sent):
word = A[start:i+1] word = A[start:i+1]
if i == len(A): if i == len(A):
if word in B: if word in B:
sents.append((sent + ' ' + word).strip()) sents.append((sent + ' ' + word).strip())
return return
if word in B:
if word in B: foo(i+1, i+1, sent + ' ' + word)
foo(i+1, i+1, sent + ' ' + word) foo(i+1, start, sent)
foo(i+1, start, sent) foo(0, 0, '')
foo(0, 0, '')
``` ```