数据结构实验之栈与队列六：下一较大值（二）（SDUT 3333）

#include <bits/stdc++.h>
using namespace std;
int a[1000006];
int b[1000006];
int sta[100006];
int main()
{
    int t,n,i,j,top;
    while(~scanf("%d",&t))
    {
        while(t--)
        {
            scanf("%d",&n);
            for( i = 1; i <= n; i ++)
            {
                scanf("%d", &a[i]);
            }
            top = 0;
            b[n] = -1;
            for(i = n - 1; i >= 1; i --)
            {
                if(a[i + 1] > a[i])
                {
                    b[i] = a[i + 1];
                    sta[top ++] = b[i];
                   // cout << "sta[top] = "<< sta[top - 1] << endl;
                 }
                else {
                    int f = 1;
                    while(top)
                    {
                       // cout << "top = " <<top << endl;
                        if(sta[top - 1] > a[i])
                        {
                            b[i] = sta[top - 1];
                            f = 0;
                            break;
                        }
                        top --;
                    }
                    if(top == 0 || f  == 1) b[i] = -1;
                }
            }
            for(i = 1; i <= n; i ++)
            {
                printf("%d-->%d
",a[i],b[i]);
            }
            if(t != 0) printf("
");
        }

    }
    return 0;
}