almostSorted.cfm

<cfscript>
tests = [
    // sorted
     [true,[1,2,3,4,5]]
    ,[true,[2,4,6,8,10]]
    
    // 1 swap
    ,[true,[1,2,3,5,4]]
    ,[true,[5,2,3,4,1]]
    ,[true,[1,2,3,5,3]]
    
    // +1 swap
    ,[false,[5,2,3,1,4]]
    ,[false,[2,3,1,5,4]]
    ,[false,[5,1,2,3,4]]
    ,[false,[2,3,1,5,4]]
    ,[false,[2,3,1,4,5]]
    ,[false,[1,2,3,5,2]]
    
];

function diff(a1, a2) {
    var diff = []

    for (i = 1; i <= ArrayLen(a1); i++) {
        if(a1[i] != a2[i]){
            diff.append(a1[i])
        }
    }

    return diff;
}

function isAlmostSorted(a){
    var sorted = duplicate(a).sort("numeric");
    var difference = []
    
    if (a.equals(sorted)){
        return true;
    }
    else{        
        difference = diff(a, sorted);
        if( len(difference) lte 2 ){
            return true
        }       
    }
    
    return false;
}

for (test in tests) {

    result = isAlmostSorted(test[2]);

    writeoutput("test " & serializeJSON(test[2]) & " : " & (result == test[1] || (!test[1] && result < 0) ? "pass " & (!!result) : "fail - got "&result) & "<br />");
    
    
}
</cfscript>