Maximum and minimum sums from two numbers with digit replacements | Find new value of x after replacing digit " from " to " to " ; Required digit found , replace it ; Returns maximum and minimum possible sums of x1 and x2 if digit replacements are allowed . ; We always get minimum sum if we replace 6 with 5. ; We always get maximum sum if we replace 5 with 6. ; Driver code
< ? php function replaceDig ( $ x , $ from , $ to ) { $ result = 0 ; $ multiply = 1 ; while ( $ x > 0 ) { $ reminder = $ x % 10 ; if ( $ reminder == $ from ) $ result = $ result + $ to * $ multiply ; else $ result = $ result + $ reminder * $ multiply ; $ multiply *= 10 ; $ x = $ x / 10 ; } return $ result ; } function calculateMinMaxSum ( $ x1 , $ x2 ) { $ minSum = replaceDig ( $ x1 , 6 , 5 ) + replaceDig ( $ x2 , 6 , 5 ) ; $ maxSum = replaceDig ( $ x1 , 5 , 6 ) + replaceDig ( $ x2 , 5 , 6 ) ; echo " Minimum sum = " ▁ , ▁ $ minSum , " " ; STRNEWLINE TABSYMBOL echo ▁ " Maximum sum = " } $ x1 = 5466 ; $ x2 = 4555 ; calculateMinMaxSum ( $ x1 , $ x2 ) ; ? >