uva 11078 Open Credit System

#include <cstdlib>
#include <iostream>
#include <stdio.h>
#include <algorithm>

using namespace std;

const int MAX = 100000+5;

int a[MAX];

int main(int argc, char *argv[])
{

int t,n;
scanf("%d",&t);
while(t--)
{
scanf("%d",&n);
for(int i = 0; i < n; i++)
{
scanf("%d",a+i);
}

int m = a[0],ans = a[0] - a[1];
for(int i = 1; i < n; i++)
{
ans = max(m - a[i],ans);
m = max(m,a[i]);
}

printf("%d\n",ans);
}

//system("PAUSE");
return EXIT_SUCCESS;
}