CSP201403-1: reverse number, csp201403-1 reverse number

CSP201403-1: reverse number, csp201403-1 reverse number

Introduction:CSP (http://www.cspro.org/lead/application/ccf/login.jsp) is a "Computer vocational qualification certification" examination initiated by CCF, perform capability certification for professionals in computer software development, software testing, information management, and other fields. The subjects of certification are those who are engaged in or will be engaged in IT professional technical and technical management personnel, as well as review subjects for university recruitment and postgraduate students.

 

• Problem description

There are N non-zero and different integers. Compile a program to find the number of pairs of the opposite numbers (a and-a are a pair of opposite numbers ).

• Input Format

The first line contains a positive integer N. (1≤n ≤500 ).

The second behavior is N non-zero integers separated by a single space. The absolute value of each number cannot exceed 1000, so that these integers are different.

• Output Format

Only one integer is output, that is, the number of pairs in the N number.

• Sample Input

5

1 2 3-1-2

• Sample output

2

 

• Source code

# Include <stdio. h> # Include <stdlib. h> # Include <memory. h>   Int main (void) { Int n; // number Scanf ("% d", & n ); Int result = 0; Int * input = (int *) malloc (sizeof (int) * n ); Memset (input, 0, sizeof (int) * n ); For (int I = 0; I <n; I ++) { Scanf ("% d", input + I ); } For (int I = 0; I <n; I ++) { For (int j = I + 1; j <n; j ++) { If (input [I] + input [j] = 0) { Result + = 1; } } } Printf ("% d \ n", result ); Free (input ); Return 0; }