Hi,
Im doing a multiplication of two large integers which are store in arrays(such as 2345 is in array as 2 in a[0], 3 in a[1] and so on)like this im storing integers in two arrays.The logic i have used is explained with code below,
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class large{
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int no[SIZE]; //array is used to store the large number. Each digit of a the number is stored as an element..
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// 123 is stored as no[3]={1,2,3}
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public:
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large operator *(large& x){ // overload the * operator
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/*
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34 x 46
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-------
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204 // these values are stored in the
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136 // two dimensional array mat[][];
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-------
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1564 // this the value stored in "large ret"
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*/
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large ret;
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int carry=0;
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int mat[2*SIZE+1][2*SIZE]={0};
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for(int i=SIZE-1;i>=0;i--){
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for(int j=SIZE-1;j>=0;j--){
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carry += no[i]*x.no[j];
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if(carry < 10){
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mat[i][j-(SIZE-1-i)]=carry;
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carry=0;
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}
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else{
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mat[i][j-(SIZE-1-i)]=carry%10;
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carry=carry/10;
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}
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}
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}
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for( i=1;i<SIZE+1;i++){
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for(int j=SIZE-1;j>=0;j--){
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carry += mat[i][j]+mat[i-1][j];
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if(carry < 10){
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mat[i][j]=carry;
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carry=0;
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}
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else{
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mat[i][j]=carry%10;
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carry=carry/10;
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}
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}
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}
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for( i=0;i<SIZE;i++)
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ret.no[i]=mat[SIZE][i];
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return ret;
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}
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large (){
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for(int i=0;i<SIZE;i++)
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no[i]=0;
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}
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large (string _no){
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for(int i=0;i<SIZE;i++)
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no[i]=0;
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int index=SIZE-1;
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for( i=_no.length()-1;i>=0;i--,index--){
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no[index]=_no[i]-'0';
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}
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}
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void print(){ //print the large number
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int start=0;
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for(int i=0;i<SIZE;i++)
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if(no[i]!=0){
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start=i;
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break; // find the first non zero digit. store the index in start.
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}
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for( i=start;i<SIZE;i++) // print the number starting from start till the end of array.
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cout<<no[i];
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cout<<endl;
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return;
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}
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};
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After multiplying the integers i store it in matrix form my problem is in storing in the matrix .If i do according to above program im unable to that..so plz anyone help me to sort out this problem.
thank u
