题解 | #接雨水问题#

/**
 * max water
 * @param arr int整型一维数组 the array
 * @return long长整型
 */
function maxWater( arr ) {
    // write code here
    let l = 0, r = arr.length - 1, res = 0;
    let lm = -Infinity, rm = -Infinity;
    while(l < r){
        lm = Math.max(lm, arr[l]);
        rm = Math.max(rm, arr[r]);
        if(lm > rm){
            res += rm - arr[r];
            r--;
        }else{
            res += lm - arr[l];
            l++;
        }
    }
    return res;
}
module.exports = {
    maxWater : maxWater
};