B. OR in Matrix
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.
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).
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.
2 2 1 0 0 0
NO
2 3 1 1 1 1 1 1
YES 1 1 1 1 1 1
2 3 0 1 0 1 1 1
YES 0 0 0 0 1 0
这题刚开始以为要用搜索,看了别人的题解才知道不用的,因为只要把0所在的行和列都变成0,其他的都变为1就得到了原来的矩阵A,(注意:其实由B得到的矩阵不止A这一个,但是这样得到的A是所有的到矩阵的最优解,因为得到1的数是最多的。
#include<stdio.h> #include<string.h> int a[200][200],b[200][200],c[200][200]; int main() { int n,m,i,j,h,t,flag,flag1; while(scanf("%d%d",&n,&m)!=EOF) { memset(a,0,sizeof(a)); memset(b,0,sizeof(b)); memset(c,0,sizeof(c)); for(i=1;i<=n;i++){ for(j=1;j<=m;j++){ scanf("%d",&a[i][j]); b[i][j]=1; } } for(i=1;i<=n;i++){ for(j=1;j<=m;j++){ if(a[i][j]==0){ for(h=1;h<=m;h++){ b[i][h]=0; } for(t=1;t<=n;t++){ b[t][j]=0; } } } } for(i=1;i<=n;i++){ for(j=1;j<=m;j++){ flag=0; for(h=1;h<=m;h++){ if(b[i][h]==1){ flag=1;break; } } for(t=1;t<=n;t++){ if(b[t][j]==1){ flag=1;break; } } if(flag==1){ c[i][j]=1;continue; } c[i][j]=0; } } flag1=1; for(i=1;i<=n;i++){ for(j=1;j<=m;j++){ if(c[i][j]!=a[i][j]){ flag1=0;break; } } if(flag1==0)break; } if(flag1==0){ printf("NO\n");continue; } printf("YES\n"); for(i=1;i<=n;i++){ for(j=1;j<=m;j++){ if(j!=m)printf("%d ",b[i][j]); else printf("%d\n",b[i][j]); } } } return 0; }