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The first fit memory allocation strategy is a technique used in operating systems to
allocate memory to processes. It involves searching for the first available memory
partition or hole that is large enough to accommodate the process. The operating
system starts searching from the beginning of the memory and assigns the process to
the first suitable free partition it encounters. Here's how the first fit algorithm works:
1. The operating system maintains a list of memory partitions, each with its size
and status (free or occupied).
2. When a process needs to be allocated memory, the operating system searches
the list of partitions from the beginning.
3. It looks for the first partition that is both free and large enough to
accommodate the process.
4. Once a suitable partition is found, the process is allocated to that partition, and
the status of the partition is updated to "occupied."
5. If no suitable partition is found, the process may not be allocated memory, or it
may be placed in a waiting queue until memory becomes available.
The first fit strategy has the advantage of being the fastest search algorithm because it
only needs to search the first block that is sufficient to assign a process. However, it
may suffer from the problem of not allowing processes to take space even if it was
possible to allocate memory. This can lead to suboptimal memory utilization and
fragmentation.

Compiler: CodeBlocks
Language: C

Source Code
#include <stdio.h>
int main() {
int bsize[10], psize[10], bno, pno, flags[10], allocation[10], i, j;
for(i = 0; i < 10; i++) {
flags[i] = 0;
allocation[i] = -1;
}
printf("Enter the number of memory blocks: ");
scanf("%d", &bno);
printf("Enter the size of each memory block: \n");
for(i = 0; i < bno; i++) {
scanf("%d", &bsize[i]);
}
printf("Enter the number of processes: ");
scanf("%d", &pno);
printf("Enter the size of each process: \n");
for(i = 0; i < pno; i++) {
scanf("%d", &psize[i]);
}
for(i = 0; i < pno; i++) {
for(j = 0; j < bno; j++) {
if(flags[j] == 0 && bsize[j] >= psize[i]) {
allocation[i] = j;
flags[j] = 1;
break;
}
}
}
printf("\nProcess No.\tProcess Size\tBlock no.\n");
for(i = 0; i < pno; i++) {
printf("%d\t\t%d\t\t", i+1, psize[i]);
if(allocation[i] != -1) {
printf("%d\n", allocation[i]+1);
} else {
printf("Not Allocated\n");
}
}
return 0;
}
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