doukaku17_1.js

"use strict";

function solve(input) {
    var num = parseInt(input);
    if(num <= 2) return "-";
    var limit   = num / 2 | 0;
    var results = [];
    var high, low;

    for(var base = 2; base <= limit; base++) {
        var n       = num;
        var isPalin = true;
        var scale   = Math.pow(base, Math.log(n) / Math.log(base) | 0);
        var base_i  = 1 / base;

        while(base <= scale) {
            high  = n / scale | 0;
            low   = n % base;
            if(high !== low) {
                isPalin = false;
                break;
            }
            n     = (n - scale * high) * base_i | 0;
            scale = scale * base_i * base_i;
        }
        if(isPalin) {
            results.push(base);
        }
    }
    results.push(num - 1);
    return results.join(",");
}

function test(input, expected) {
    var result = solve(input);
    if(result !== expected) {
        console.log("-------------\ninput = %s\n\nexpected = %s\nresult   = %s", input, expected, result);
    }
}

test( "17301",  "5,38,100,218,236,5766,17300"                   );
test( "2",      "-"                                             );
test( "1",      "-"                                             );
test( "3",      "2"                                             );
test( "4",      "3"                                             );
test( "5",      "2,4"                                           );
test( "6",      "5"                                             );
test( "10",     "3,4,9"                                         );
test( "101",    "10,100"                                        );
test( "1001",   "10,25,76,90,142,1000"                          );
test( "10001",  "10,24,30,42,80,100,136,10000"                  );
test( "1212",   "22,100,201,302,403,605,1211"                   );
test( "123412", "62,100,205,215,30852,61705,123411"             );
test( "5179",   "5178"                                          );
test( "4919",   "4918"                                          );
test( "5791",   "5790"                                          );
test( "5498",   "2748,5497"                                     );
test( "453",    "150,452"                                       );
test( "134",    "66,133"                                        );
test( "8489",   "27,652,8488"                                   );
test( "1234",   "22,616,1233"                                   );
test( "5497",   "41,238,5496"                                   );
test( "4763",   "19,35,432,4762"                                );
test( "3974",   "17,27,1986,3973"                               );
test( "3521",   "44,55,502,3520"                                );
test( "5513",   "20,38,53,148,5512"                             );
test( "8042",   "23,29,60,4020,8041"                            );
test( "7442",   "37,60,121,3720,7441"                           );
test( "4857",   "25,1618,4856"                                  );
test( "22843",  "49,69,91,141,430,22842"                        );
test( "194823", "84,121,21646,64940,194822"                     );
test( "435697", "160,169,235,626,1822,435696"                   );
test( "142",    "3,7,70,141"                                    );
test( "886",    "5,14,442,885"                                  );
test( "3102",   "7,65,93,140,281,516,1033,1550,3101"            );
test( "17326",  "11,28,99,105,8662,17325"                       );
test( "32982",  "13,72,238,477,716,1433,5496,10993,16490,32981" );
test( "36",     "5,8,11,17,35"                                  );
test( "37",     "6,36"                                          );
test( "251",    "8,250"                                         );
test( "252",    "5,10,17,20,27,35,41,62,83,125,251"             );
test( "253",    "12,14,22,252"                                  );
test( "6643",   "2,3,9,81,90,510,948,6642"                      );
test( "5040",   "71,79,83,89,104,111,119,125,139,143,167,179,209,239,251,279,314,335,359,419,503,559,629,719,839,1007,1259,1679,2519,5039"                         );
test( "9240",   "23,38,62,104,109,119,131,139,153,164,167,209,219,230,263,279,307,329,384,419,439,461,615,659,769,839,923,1154,1319,1539,1847,2309,3079,4619,9239" );