In DNA strings, symbols 'A' and 'T' are complements of each other, as are 'C' and 'G'. The reverse complement of a DNA string s is the string sc formed by reversing the symbols of s, then taking the complement of each symbol (e.g., the reverse complement of "GTCA" is "TGAC"). Given: A DNA string s of length at most 1000 bp. Return: The reverse complement sc of s. Sample Dataset AAAACCCGGT Sample Output ACCGGGTTTT
读取文件时，每个碱基做互补碱基的mapping，存入时使用反向，也就是后面的碱基存在链表的前面。最后只需遍历链表，把结果打印出来。
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 | #include<stdio.h> #include<stdlib.h> typedef struct ntNode { char NT; /* nucleotide */ struct ntNode *next; } ntNode; int main() { FILE *INFILE; INFILE = fopen("../DATA/rosalind_revc.txt", "r"); ntNode *head, *curr; head= NULL; char nt; while ( (nt = fgetc(INFILE)) != EOF) { curr = malloc(sizeof(ntNode)); switch(nt) { case 'A': nt = 'T'; break; case 'C': nt = 'G'; break; case 'G': nt = 'C'; break; case 'T': nt = 'A'; break; default: nt = ' '; } curr->NT = nt; curr->next = head; head = curr; } curr = head; while(curr) { printf("%c", curr->NT); curr = curr->next; } printf("\n"); return 0; } |