PTA甲 1104. Sum of Number Segments (20)
来源:互联网 发布:java 抽象方法 static 编辑:程序博客网 时间:2024/06/06 00:02
1104. Sum of Number Segments (20)
Given a sequence of positive numbers, a segment is defined to be a consecutive subsequence. For example, given the sequence {0.1, 0.2, 0.3, 0.4}, we have 10 segments: (0.1) (0.1, 0.2) (0.1, 0.2, 0.3) (0.1, 0.2, 0.3, 0.4) (0.2) (0.2, 0.3) (0.2, 0.3, 0.4) (0.3) (0.3, 0.4) (0.4).
Now given a sequence, you are supposed to find the sum of all the numbers in all the segments. For the previous example, the sum of all the 10 segments is 0.1 + 0.3 + 0.6 + 1.0 + 0.2 + 0.5 + 0.9 + 0.3 + 0.7 + 0.4 = 5.0.
Input Specification:
Each input file contains one test case. For each case, the first line gives a positive integer N, the size of the sequence which is no more than 105. The next line contains N positive numbers in the sequence, each no more than 1.0, separated by a space.
Output Specification:
For each test case, print in one line the sum of all the numbers in all the segments, accurate up to 2 decimal places.
Sample Input:40.1 0.2 0.3 0.4Sample Output:
5.00
一道很有意思的小题一开始没有考虑复杂度直接用了n方的,没想到后面两个数据过不了。后来观察规律,发现数组中数出现的次数是有规律的所以在输入的过程中就可以同时进行求和了。
ac代码
#include <stdio.h>
double a[100005];
int main()
{
int i,j,n;
double sum=0;
scanf("%d",&n);
for(i=0;i<n;i++)
{
scanf("%lf",&a[i]);
double sumTmp = a[i] * (n - i) *(i + 1) ;
sum += sumTmp ;
}
printf("%.2lf",sum);
return 0;
}
15分代码
#include <stdio.h>
float a[100005];
int main()
{
int i,j,n;
float sum=0,last=0,ans=0;
scanf("%d",&n);
for(i=0;i<n;i++)
{
scanf("%f",&a[i]);
}
for(i=0;i<n;i++)
{
ans=0;
for(j=i;j<n;j++)
{
ans+=a[j];
sum+=ans;
}
}
printf("%.2f",sum);
return 0;
}
- PTA甲 1104. Sum of Number Segments (20)
- 【PAT】1104. Sum of Number Segments (20)
- 1104. Sum of Number Segments (20)
- 1104. Sum of Number Segments (20)
- 1104. Sum of Number Segments (20)
- PAT 1104. Sum of Number Segments (20)
- 1104. Sum of Number Segments (20)
- 1104. Sum of Number Segments (20)
- PAT 1104. Sum of Number Segments (20)
- 1104. Sum of Number Segments (20)
- [pat]1104. Sum of Number Segments (20)
- 1104. Sum of Number Segments (20)
- 1104. Sum of Number Segments (20)
- 1104. Sum of Number Segments (20)
- 1104. Sum of Number Segments (20)
- 1104. Sum of Number Segments (20)
- PAT 1104. Sum of Number Segments (20)
- 1104. Sum of Number Segments (20)
- RxJava2.0使用
- windows7下硬盘安装linux
- Win10通知区域图标设置(找回win7的“通知区域图标”)
- 04. Servlet 异常处理&日志调试
- SRS(simple-rtmp-server)流媒体服务器源码分析--HLS切片
- PTA甲 1104. Sum of Number Segments (20)
- JAVASCRIPT的第二天
- 丑数
- 设计模式学习—命令模式
- 大数据入门基础:Hadoop简介
- 网易2016研发工程师编程题--完全解析
- 从概念到底层技术,一文看懂区块链架构设计(附知识图谱)
- #425
- HDU-2017 多校训练赛1-1002-Balala Power!