ds-algo-study
Version:
Just experimenting with publishing a package
34 lines (30 loc) • 1.13 kB
JavaScript
/*
* Given two sequences, find the length of longest subsequence present in both of them.
* A subsequence is a sequence that appears in the same relative order, but not necessarily contiguous.
* For example, "abc", "abg", "bdf", "aeg", ‘"acefg", ..etc are subsequences of "abcdefg"
*/
function longestCommonSubsequence( x, y, str1, str2, dp ) {
if ( x === -1 || y === -1 ) {
return 0
} else {
if ( dp[ x ][ y ] !== 0 ) {
return dp[ x ][ y ]
} else {
if ( str1[ x ] === str2[ y ] ) {
dp[ x ][ y ] = 1 + longestCommonSubsequence( x - 1, y - 1, str1, str2, dp )
return dp[ x ][ y ]
} else {
dp[ x ][ y ] = Math.max( longestCommonSubsequence( x - 1, y, str1, str2, dp ), longestCommonSubsequence( x, y - 1, str1, str2, dp ) )
return dp[ x ][ y ]
}
}
}
}
function main() {
const str1 = 'ABCDGH'
const str2 = 'AEDFHR'
const dp = new Array( str1.length + 1 ).fill( 0 ).map( x => new Array( str2.length + 1 ).fill( 0 ) )
const res = longestCommonSubsequence( str1.length - 1, str2.length - 1, str1, str2, dp )
console.log( res )
}
main()