A. Calculating Function
time limit per test
1 second
memory limit per test
256 megabytes
input
standard input
output
standard output
For a positive integer n let's define a function f:
f(n)?=??-?1?+?2?-?3?+?..?+?(?-?1)nn
Your task is to calculate f(n) for a given integer n.
Input
The single line contains the positive integer n (1?≤?n?≤?1015).
Output
Print f(n) in a single line.
Sample test(s)
input
output
input
output
-3
Note
f(4)?=??-?1?+?2?-?3?+?4?=?2
f(5)?=??-?1?+?2?-?3?+?4?-?5?=??-?3
#include#include #include #include using namespace std;int main(){#ifdef xxz freopen("in.txt","r",stdin);#endif // xxz long long n; while(cin>>n) { long long sum = 0; sum += n/2; if(n%2) sum -= n; cout
B. OR in Matrix
time limit per test
1 second
memory limit per test
256 megabytes
input
standard input
output
standard output
Let's define logical OR as an operation on two logical values (i. e. values that belong to the set {0,?1}) that is equal to 1 if either or both of the logical values is set to 1, otherwise it is 0. We can define logical OR of three or more logical values in the same manner:
where is equal to 1 if some ai?=?1, otherwise it is equal to 0.
Nam has a matrix A consisting of m rows and n columns. The rows are numbered from 1 to m, columns are numbered from 1 to n. Element at row i (1?≤?i?≤?m) and column j (1?≤?j?≤?n) is denoted as Aij. All elements of A are either 0 or 1. From matrix A, Nam creates another matrix B of the same size using formula:
.
(Bij is OR of all elements in row i and column j of matrix A)
Nam gives you matrix B and challenges you to guess matrix A. Although Nam is smart, he could probably make a mistake while calculating matrix B, since size of A can be large.
Input
The first line contains two integer m and n (1?≤?m,?n?≤?100), number of rows and number of columns of matrices respectively.
The next m lines each contain n integers separated by spaces describing rows of matrix B (each element of B is either 0 or 1).
Output
In the first line, print "NO" if Nam has made a mistake when calculating B, otherwise print "YES". If the first line is "YES", then also print mrows consisting of n integers representing matrix A that can produce given matrix B. If there are several solutions print any one.
Sample test(s)
input
2 21 00 0
output
NO
input
2 31 1 11 1 1
output
YES1 1 11 1 1
input
2 30 1 01 1 1
output
YES0 0 00 1 0把A数组全部赋值为1，然后根据B数组再把A数组一些元素赋值为0，最后算A和B比较，注意如果开始把A全部初始化为0，很难算出来（稍微思考就知道了，如果全部赋值为0，那么1的时候你不知道把A的哪些赋值为1，就容易出错）
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