[codility] GenomicRangeQuery

// you can write to stdout for debugging purposes, e.g.
// console.log('this is a debug message');

// console.log('this is a debug message');

function solution(S, P, Q) {
    // write your code in JavaScript (Node.js 8.9.4)

    let start = 0;
    let stop = 0;

    let prefixSum = []; 
    let str = [];
    for(let i =0; i < P.length; i++) {

        start = (P[i]);
        stop = (Q[i]+1);
        str = S.substring(start,stop);

        if(str.indexOf("A") !== -1){
           prefixSum.push(1);
        }else if(str.indexOf("C")!== -1){
            prefixSum.push(2);
        }else if(str.indexOf("G") !== -1){            
            prefixSum.push(3);
        }else if(str.indexOf("T") !== -1){            
            prefixSum.push(4)
        }

    }

    return prefixSum;
}