Code conversion: C++ to C#

[abeero]

I need some help please.

I have to convert this code from c++ to c#.but i don't know how can i do it.and i have to do it ASAP.

can you convert it for me please?

thanks..im waiting you.


the code :

#include "mpi.h"
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <math.h>

int rank, size;

#define MAX_ALLOC_SIZE 1000000000

int isValidAlloc(int alloc){
    return (alloc>0&&alloc<MAX_ALLOC_SIZE);
}

void swap(int* data, int i, int j){
    int t;
    t = data[i];
    data[i] = data[j];
    data[j] = t;
}

//  Q-sort algorithm
void myqsort(int* data, int left, int right){
    int i,last;
    if(left>=right||left<0||right<0)
        return;
    //swap(data,left,(left+right)/2);
    last = left;
    for(i=left+1;i<=right;i++)
        if(data[i]<data[left])
            swap(data,++last,i);
    swap(data,left,last);
    myqsort(data,left,last-1);
    myqsort(data,last+1,right);
}

void qSort(int* buf , int bufSize){
    myqsort(buf, 0, bufSize-1);
}

//  Bubble sort algorithm
void bubbleSort(int* buf, int bufSize){
    for(int i=0;i<bufSize;i++)
        for(int j=0;j<bufSize-i-1;j++){
            if(buf[j]>buf[j+1])
                swap(buf, j, j+1);
        }
}

//  Merging sort algorithm
void merge(int* input, int* output, int bufSize, int totalSize){
    int* track=(int*)calloc(size, sizeof(int));
    if(!track)
        MPI_Abort(MPI_COMM_WORLD, -1);
    for(int i=0;i<totalSize;i++){
        int min=INT_MAX;
        int minsite=-1;
        for(int j=0;j<size;j++){
            if(track[j]<bufSize&&*(input+bufSize*j+track[j])<=min){
                min=*(input+bufSize*j+track[j]);
                minsite=j;
            }
        }
        output[i]=min;
        track[minsite]++;
    }
    if(track)
        free(track);
}

//  Reads the sequence data and scatters to all the processes.
void init_root(char* input_fn, int** smallBuffer, int* bufSize, int* cnt){
    FILE* fp=fopen(input_fn, "r");

    if(!fp){
        printf("Can't find the file: %s\n.", input_fn);
        fflush(stdout);
        MPI_Abort(MPI_COMM_WORLD, -1);
    }

    fscanf_s(fp, "%d", cnt);

    *bufSize=*cnt/size+1;

    int toAlloc=sizeof(int)**bufSize*size;
    if(!isValidAlloc(toAlloc))
        MPI_Abort(MPI_COMM_WORLD, -1);
    int* bigBuffer=(int*)malloc(toAlloc);
    if(!bigBuffer)
        MPI_Abort(MPI_COMM_WORLD, -1);

    for(int i=0;i<*bufSize*size;i++)
        *(bigBuffer+i)=INT_MAX;

    toAlloc=sizeof(int)**bufSize;
    if(!isValidAlloc(toAlloc))
        MPI_Abort(MPI_COMM_WORLD, -1);
    *smallBuffer=(int*)malloc(toAlloc);
    if(!smallBuffer)
        MPI_Abort(MPI_COMM_WORLD, -1);

    int proc=0;
    int iter=0;
    for(int i=0;i<*cnt;i++){
        fscanf_s(fp, "%d", bigBuffer+proc**bufSize+iter);
        if(++proc==size){
            proc=0;
            iter++;
        }
    }

    if(fp)
        fclose(fp);

    MPI_Bcast(bufSize, 1, MPI_INT, 0, MPI_COMM_WORLD);
    MPI_Scatter(bigBuffer, *bufSize, MPI_INT, *smallBuffer, *bufSize, MPI_INT, 0, MPI_COMM_WORLD);
    if(bigBuffer)
        free(bigBuffer);

}

//  Gets the sequence data scattered from the root process.
void init_worker(int** smallBuffer, int* bufSize){
    int* bigBuffer=NULL;
    MPI_Bcast(bufSize, 1, MPI_INT, 0, MPI_COMM_WORLD);

    int toAlloc=sizeof(int)**bufSize;
    if(!isValidAlloc(toAlloc))
        MPI_Abort(MPI_COMM_WORLD, -1);
    *smallBuffer=(int*)malloc(toAlloc);
    if(!smallBuffer)
        MPI_Abort(MPI_COMM_WORLD, -1);

    MPI_Scatter(bigBuffer, *bufSize, MPI_INT, *smallBuffer, *bufSize, MPI_INT, 0, MPI_COMM_WORLD);
}

void main(int argc, char* argv[]){
    MPI_Init(&argc, 0);
    MPI_Comm_rank(MPI_COMM_WORLD, &rank);
    MPI_Comm_size(
        MPI_COMM_WORLD,
        &size
        );

    if(argc!=3){
        if(rank==0){
            printf("Usage: mpiexec -np <nProcs> sort.exe <input_file> <output_file>\n");
            fflush(stdout);
        }
        MPI_Finalize();
        return;
    }

    char* input_fn=argv[1];
    char* output_fn=argv[2];

    int* inBuf=NULL;
    int bufSize=0;
    int totalSize=0;

    if(rank==0)
        init_root(input_fn, &inBuf, &bufSize, &totalSize);
    else
        init_worker(&inBuf, &bufSize);

    int *tmpBuf,*finalBuf;
    tmpBuf=finalBuf=NULL;
    if(rank==0)
    {
        int toAlloc=sizeof(int)*bufSize*size;
        if(!isValidAlloc(toAlloc))
            MPI_Abort(MPI_COMM_WORLD, -1);
        tmpBuf=(int*)malloc(toAlloc);
        if(!tmpBuf)
            MPI_Abort(MPI_COMM_WORLD, -1);

        toAlloc=sizeof(int)*totalSize;
        if(!isValidAlloc(toAlloc))
            MPI_Abort(MPI_COMM_WORLD, -1);
        finalBuf=(int*)malloc(toAlloc);
        if(!finalBuf)
            MPI_Abort(MPI_COMM_WORLD, -1);

    }

    //  Chooses a sorting algorithm for each process respectively.
    void (*mysort)(int*, int)=(rank%2?qSort:bubbleSort);

    //(*mysort) (int*, int) = qSort ;
    //  Sorting
    mysort(inBuf, bufSize);

    //  Gathers all the sorted sections back to the root process.
    MPI_Gather(inBuf, bufSize, MPI_INT, tmpBuf, bufSize, MPI_INT, 0, MPI_COMM_WORLD);

    if(rank==0)
    {

        //  Merges all the well-sorted sequence sections together to the final result.
        merge(tmpBuf, finalBuf, bufSize, totalSize);

        //  Outputs to file.
        FILE* fp=fopen(output_fn, "w");
        if(!fp)
            MPI_Abort(MPI_COMM_WORLD, -1);
        fprintf(fp, "%d\n", totalSize);
        for(int i=0;i<totalSize;i++){
            fprintf(fp, "%d ", *(finalBuf+i));
        }
        if(fp)
            fclose(fp);
    }

    if(inBuf)
        free(inBuf);
    MPI_Finalize();
}

[Bassem]

These may help you StreamReader, StreamWriter and Unsafe code.
Try and post if any problem.

[PRR]

C++ and C# are different languages... It wont be easy to convert c++ code to C# in one step... You can look Lutz Roeder's Reflector

[tlhintoq]

can you convert it for me please?

No. If you want to offer this as a paid job request there is a forum for that... but otherwise the people hear are volunteers who are happy to help you learn, but they won't do your work for you.