View Code of Problem 10

#include <stdio.h>
int main(){
	int N,i,j,num[4];
  	scanf("%d",&N);
  	for(i=0; i<N; i++){
          	int k=0;
  		for(j=0; j<4; j++)
                  scanf("%d",&num[j]);
          	for(j=3;j>=0;--j){
        	    if(a[j]==0)	++k;
        	    else if(a[j]!=0&&k!=0){
        		a[j+k]=a[j];
        		a[j]=0;
        	    }		
       	    	}
                for(j=3;j>0;--j)
                      {
                         if(a[j]==a[j-1]){
                              a[j]=a[j]*2;
                              a[j-1]=0;
                              for(k=j-1;k>0;--k){
                                  a[k]=a[k-1];
                                  a[k-1]=0;
                              }
                         }
                      }
          	for(j=0;j<3;++j)
        	    printf("%d ",a[j]);
        	printf("%d\n",a[j]);
  }
  return 0;
}
/*
Main.c: In function 'main':
Main.c:10:17: error: 'a' undeclared (first use in this function)
              if(a[j]==0) ++k;
                 ^
Main.c:10:17: note: each undeclared identifier is reported only once for each function it appears in
*/