#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <stdbool.h>
int main ( int argc, char * argv[] ) {
int m, M;
scanf( "%d", &M );
for( m = 0; m < M; m++) {
if( m > 0 ) printf( "\n" );
int n;
scanf( "%d", &n );
double a_0, a_np1;
double * c_n = malloc( sizeof( double ) * n );
scanf( "%lf %lf", &a_0, &a_np1 );
int i;
for( i = 0; i < n; i++ ) scanf( "%lf", c_n + i );
int c_a = n + 1;
double constant = 0, last_constant = 0;
constant = a_0 * 2;
last_constant = constant;
constant = ( constant + c_n [ 0 ] ) * 2 - a_0;
for( i = 1; i < n; i++) {
double t = constant;
constant = ( constant + c_n[ i ] ) * 2 - last_constant;
last_constant = t;
}
double a = (constant - a_np1) / c_a;
double a_1 = a_0 * 2 - a;
/* printf("const = %f, c_a = %d, a=%f, a_1=%f\n", constant, c_a, a, a_1); */
printf( "%.2lf\n", a_1 );
free( c_n );
}
return 0;
}
10014 - Simple calculations
最新推荐文章于 2017-09-06 15:16:57 发布