Given a sequence of integers S = {S1, S2, . . . , Sn}, you should determine what is the value of the
maximum positive product involving consecutive terms of S. If you cannot find a positive sequence,
you should consider 0 as the value of the maximum product.
Input
Each test case starts with 1 ≤ N ≤ 18, the number of elements in a sequence. Each element Si
is
an integer such that −10 ≤ Si ≤ 10. Next line will have N integers, representing the value of each
element in the sequence. There is a blank line after each test case. The input is terminated by end of
file (EOF).
Output
For each test case you must print the message: ‘Case #M: The maximum product is P.’, where
M is the number of the test case, starting from 1, and P is the value of the maximum product. After
each test case you must print a blank line.
Sample Input
3
2 4 -3
5
2 5 -1 2 -1
Sample Output
Case #1: The maximum product is 8.
Case #2: The maximum product is 20.
題意:輸入n個元素組成的序列S,你需要找出一個乘積最大的連續子序列 。如果這個最大的乘積不是正數,就輸出0(表示無解)。 1<=n<=18 -10<=S<=10
輸出格式 每輸出一組案例就空一行(注意)
題目分析:連續子序列有兩個要素:起點和重點。所以只要枚舉起點和終點就好。由於每個元素與的最大值不會超過10,且不超過18個元素,最大乘積不會超過10的18次方。所以可以用long long儲存(試了一下,用int的話,輸出18個10的結果不對,int存不下)
代碼如下:(媽的,剛開始想到3重循環去了,還傻逼的循環了一個len表示子序列的長度,盡管試了很多案例都對了,就是不能過。重想了一下,抱著試一試的心態,寫了,然後TM就過了,也是RLGL.....)
1 #include <stdio.h> 2 int a[20]; 3 int main() 4 { 5 int n,N=0,c2=0; 6 while(scanf("%d",&n)==1) 7 { 8 long long c,c2=0; 9 ++N; 10 for(int i=0; i<n; i++) 11 scanf("%d",&a[i]); 12 for(int q=0;q<n;q++) 13 { 14 c=1; 15 for(int z=q;z<n;z++) 16 { 17 c*=a[z]; 18 if(c>c2) 19 c2=c; 20 } 21 } 22 if(c2<=0) 23 printf("Case #%d: The maximum product is 0.\n\n",N); 24 else 25 printf("Case #%d: The maximum product is %lld.\n\n",N,c2); 26 } 27 return 0; 28 }