1513-number-of-substrings-with-only-1s

DevGod

Elf Vtuber

Caution

DevGod needs to write an editorial for this problem!

js

/**
 * @param {string} s
 * @return {number}
 */
var numSub = function(s) {
    const MOD = 10**9 + 7;
    return s.split("0").reduce(
        (sum,el)=>sum = (sum+(el.length/2)*(el.length+1))%MOD, 0
    )%MOD;
};