0001 uint64_t mr1Pass(uint64_t H[], Rank n) { //单趟扫描版
0002    Stack<Rank> SR; //次栈顶、栈顶总是s[r]-1与r，当前的t = t[r]
0003    uint64_t maxRect = 0;
0004    for (Rank t = 0; t <= n; t++) { //对于以t为右限的
0005       while (!SR.empty() && (t == n || H[SR.top()] >= H[t])) { //每一个极大矩形
0006          Rank r = SR.pop(), s = SR.empty() ? 0 : SR.top()+1; //次栈顶即是左限
0007          maxRect = max(maxRect, H[r]*(t-s)); //算出面积，并择优更新
0008       } //while
0009       SR.push(t); //栈中只记录所有的H[s] = min{ H[k] | s <= k <= t }
0010    } //assert(SR.empty())
0011    SR.pop(); return maxRect; //弹出尾哨兵，返回最大面积
0012 } //每项进栈、出栈不过常数次，累计成本O(n)