armies

function solve(arr) {
    const leaders = new Map();

    for (const entry of arr) {
        if (/arrives/.test(entry)) {
            const leader = entry.match(/.+(?= arrives)/)[0];
            if (!leaders.get(leader)) {
                leaders.set(leader, new Map());
            }
        }
        else if (/:/.test(entry)) {
            let { l, a, c } = entry.match(/(?<l>[\w\s]+):\s(?<a>[\w\s]+),\s(?<c>\d+)/).groups;
            c = Number(c);

            if (leaders.has(l)) {
                leaders.get(l).set(a, c);
            }
        }
                else if (/defeated/.test(entry)) {
            const { l } = entry.match(/(?<l>.+(?=\sdefeated))/).groups;
            if (leaders.has(l)) {
                leaders.delete(l);
            }
        }
        else if (/\+/.test(entry)) {
            let [a, c] = entry.split(' + ');
            c = Number(c);
            [...leaders.keys()].forEach(l => {
                if (leaders.get(l).has(a)) {
                    const prevCount = leaders.get(l).get(a);
                    leaders.get(l).set(a, prevCount + c);
                }
            })
        }
    }
        // sort the leaders by total army count in descending. Then each army should be sorted by count in descending.
    [...leaders.keys()].forEach(a => {
        const army = leaders.get(a);
        const total = [...army.values()].reduce((x, y) => x + y, 0);;
        leaders.get(a).set('total', total);
    });
    [...leaders.entries()].sort((a, b) => {
        return b[1].get('total') - a[1].get('total');
    }).forEach(x => {
        console.log(`${x[0]}: ${x[1].get('total')}`);
        x[1].delete('total');
        [...x[1].entries()].sort((a, b) => b[1] - a[1]).forEach(a => {
            console.log(`>>> ${a[0]} - ${a[1]}`);
        })
    });
}