11. Container With Most Water

Given n non-negative integers a1, a2, ..., an, where each represents a point at coordinate (i, ai). n vertical lines are drawn such that the two endpoints of line i is at (i, ai) and (i, 0). Find two lines, which together with x-axis forms a container, such that the container contains the most water.

Note: You may not slant the container and n is at least 2.

 

public int maxArea(int[] a) {
    int i = 0;
    int j = a.length - 1;
    int maxS = 0;
    int currentS = 0;
    while (i != j) {
        currentS = (j - i) * Math.min(a[i], a[j]); //面积等于底*高
        maxS = Math.max(currentS, maxS);
        if (a[i] > a[j]) //寻找有无更高的柱子
            j--;
        else
            i++;
    }
    return maxS;
}