maximise-sum.js

// https://www.hackerrank.com/challenges/maximise-sum

function processData(input) {
    var lines = input.split('\n')
    var line = 0;
    var t = parseInt(lines[line++]);
    for (var i = 0; i < t; i++){
        var tmp = lines[line++].split(' ').map(x => parseInt(x));
        var n = tmp[0], m = tmp[1];
        var arr = lines[line++].split(' ').map(x => parseInt(x)).slice(0, n);
        console.log(solution(arr, m));
    }
} 

function solution(arr, m){
    var prefix = [];
    var sum = 0;
    var n = arr.length;
    var i, j;
    
    for (i = 0; i < n; i++){
        sum += arr[i];
        prefix[i] = {value: sum % m, index: i};
        // optimization: m-1 is the maximum we can get
        if (prefix[i].value === m-1) return m-1;
    }
    
    prefix.sort((a, b) => a.value - b.value);
    
    //console.log(prefix);
    
    var minDiff = m - prefix[n-1].value;
    //console.log(minDiff);
    
    for (i = 1; i < n; i++){
        if (prefix[i-1].index > prefix[i].index && prefix[i].value - prefix[i-1].value > 0) {
            minDiff = Math.min(minDiff, (prefix[i].value - prefix[i-1].value));
        }
    }
    
    return m - minDiff;

}

process.stdin.resume();
process.stdin.setEncoding("ascii");
_input = "";
process.stdin.on("data", function (input) {
    _input += input;
});

process.stdin.on("end", function () {
   processData(_input);
});