Description
The tests which the contractor completed were computer simulations of battlefield and hostile attack conditions. Since they were only preliminary, the simulations tested only the CATCHER's vertical movement capability. In each simulation, the CATCHER was fired at a sequence of offensive missiles which were incoming at fixed time intervals. The only information available to the CATCHER for each incoming missile was its height at the point it could be intercepted and where it appeared in the sequence of missiles. Each incoming missile for a test run is represented in the sequence only once.
The result of each test is reported as the sequence of incoming missiles and the total number of those missiles that are intercepted by the CATCHER in that test.
The General Accounting Office wants to be sure that the simulation test results submitted by the military contractor are attainable, given the constraints of the CATCHER. You must write a program that takes input data representing the pattern of incoming missiles for several different tests and outputs the maximum numbers of missiles that the CATCHER can intercept for those tests. For any incoming missile in a test, the CATCHER is able to intercept it if and only if it satisfies one of these two conditions:
The incoming missile is the first missile to be intercepted in this test.
-or-
The missile was fired after the last missile that was intercepted and it is not higher than the last missile which was intercepted.
Input
Output
Note: The number of missiles for any given test is not limited. If your solution is based on an inefficient algorithm, it may not execute in the allotted time.
Sample Input
389
207
155
300
299
170
158
65
-1
23
34
21
-1
-1
Sample Output
Test #1:
maximum possible interceptions: 6 Test #2:
maximum possible interceptions: 2
【题意】求最长下降子序列
#include<iostream>
#include<stdio.h>
#include<string.h>
using namespace std;
const int inf=0x7777777;
const int N=;
int a[N],dp[N];
int get_ans(int n)
{
int ans=;
a[]=inf;
memset(dp,,sizeof(dp));
for(int i=;i<=n;i++)
{
for(int j=i-;j>=;j--)
{
if(a[i]<=a[j])
dp[i]=max(dp[i],dp[j]+);
}
ans=max(ans,dp[i]);
}
return ans;
}
int main()
{
int cas=;
while(scanf("%d",&a[]))
{
if(a[]==-) break;
int cnt=;
while()
{
scanf("%d",&a[cnt]);
if(a[cnt]==-) break;
cnt++;
}
printf("Test #%d:\n",cas++);
printf(" maximum possible interceptions: %d\n\n",get_ans(cnt-));
}
return ;
}