题目：给定一个整形数组，数组是无重复随机无序的，要求打印出所有元素左边第一个大于该元素的值。
#include <iostream>#include <time.h>#include <stack>using namespace std;void shuffle(int a[], int n){srand(time(NULL));for(int i = 0; i < n; i++){int index = rand() % n;int tmp = a[i];a[i] = a[index];a[index] = tmp;}}void f(int a[], int n){stack<int> s;if(n <= 1)return;s.push(a[0]);for(int i = 1; i < n; i++){while(!s.empty() && a[i] > s.top()){cout<<s.top()<<','<<a[i]<<endl;s.pop();}s.push(a[i]);}}int main(int argc, char *argv[]){int *a = new int[atoi(argv[1])];for(int i = 0; i < atoi(argv[1]); i++){a[i] = i + 1;}shuffle(a, atoi(argv[1]));for(int i = 0; i < atoi(argv[1]); i++){cout<<a[i]<<' ';}cout<<endl;cout<<"------------------------------"<<endl;f(a, atoi(argv[1]));return 0;}
