Uva 10014 - Simple calculations
Simple calculations |
The Problem
There is a sequence of n+2 elements a0, a1,…, an+1 (n <= 3000; -1000 <= ai 1000). It is known that ai = (ai–1 + ai+1)/2 – ci for each i=1, 2, ..., n. You are given a0, an+1, c1, ... , cn. Write a program which calculates a1.
The Input
The first line is the number of test cases, followed by a blank line.
For each test case, the first line of an input file contains an integer n. The next two lines consist of numbers a0 and an+1 each having two digits after decimal point, and the next n lines contain numbers ci (also with two digits after decimal point), one number per line.
Each test case will be separated by a single line.
The Output
For each test case, the output file should contain a1 in the same format as a0 and an+1.
Print a blank line between the outputs for two consecutive test cases.
Sample Input
1 1 50.50 25.50 10.15
Sample Output
27.85
#include<stdio.h> #include<string.h> int main() { int T, n, i; double first, final, sum, temp, ans; scanf("%d", &T); while(T--) { scanf("%d", &n); scanf("%lf", &first); scanf("%lf", &final); for(i=1,sum=0; i<=n; ++i) { scanf("%lf", &temp); sum += 2.0*(n+1-i)*temp; } ans = n*first+final-sum; printf("%.2lf\n", ans/(n+1)); if(T != 0) printf("\n"); } return 0; }
![物役记](https://s2.ax1x.com/2019/05/26/VE5YD0.jpg)
更多内容请关注个人微信公众号 物役记 (微信号:materialchains)