# Check if it is possible to transform one string to another in Python

PythonServer Side ProgrammingProgramming

Suppose we have two strings s and t, t is in uppercase. We have to check whether we can convert s to t by performing following operations.

• Convert some lowercase letters uppercase.
• Remove all of the lowercase letters.

So, if the input is like s = "fanToM", t = "TOM", then the output will be True as we can change ‘o’ to ‘O’ then remove all other lowercase letters from s to make it t.

To solve this, we will follow these steps −

• n := size of s, m := size of t
• dp:= a matrix of size (m + 1)x(n + 1) and fill with False
• dp[0, 0] := True
• for i in range 0 to size of s - 1, do
• for j in range 0 to size of t, do
• if dp[i, j] is True, then
• if j < size of t and s[i] in uppercase is same as t[j], then
• dp[i + 1, j + 1] := True
• if s[i] is not in uppercase, then
• dp[i + 1, j] := True
• return dp[n, m]

## Example

Let us see the following implementation to get better understanding −

Live Demo

def solve(s,t):
n = len(s)
m = len(t)
dp= [[False for i in range(m+1)] for i in range(n+1)]
dp[0][0] = True
for i in range(len(s)):
for j in range(len(t)+1):
if dp[i][j] == True:
if j < len(t) and (s[i].upper() == t[j]):
dp[i + 1][j + 1] = True
if s[i].isupper()==False:
dp[i + 1][j] = True
return dp[n][m]
s = "fanToM"
t = "TOM"
print(solve(s, t))

## Input

"fanToM", "TOM"

## Output

True
Updated on 19-Jan-2021 04:37:38

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