我目前正在编写C程序来创建具有特定长度的单词列表。
例如，我有一个十个字母的字符串
ABCDEFGHIJ
并想创建一个长度为2的单词列表
AB，BC，CD，DE，EF，FG，GH，HI，IJ 。
目前我只能创建
AB，CD，EF，GH，IJ
使用我的编码
#include<stdio.h>
#include<string.h>
int main()
{
/*q=length of query sequence, W=length of substring, t=(q-w)+1*/
char array[5][3],length[3];
int i=1;
FILE *input;
input=fopen("string.txt", "r");
/*stores and prints the data from the string*/
while(fgets(length,3,input))
{
strcpy(array[i],length);
printf(">%d\n%s\n\n",i,array[i]);
i++;
}
return 0;
}
如何将数组指向从第二个字母而不是第三个字母开始的下一个单词？
谢谢。
答案 0 :(得分：0)
鉴于您的问题，您需要逐个字符地读取文件字符，而不是2个字符地读取字符：
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
int main(void)
{
char str[3] = "";
FILE *input = NULL;
if (!(input = fopen("string.txt", "r"))) {
// Error
return (EXIT_FAILURE);
}
if (!fgets(str,3,input)) {
// Error ?
}
printf("%s\n", str);
for(int c = fgetc(input); c != EOF; c = fgetc(input)) {
str[0] = str[1];
str[1] = c;
printf("%s\n", str);
}
return (EXIT_SUCCESS);
}
但是更好的方法是读取整行（如在Linux上使用getline一样），并仅显示2 char by 2 char ...
好的，这不是SO的实际工作方式，但是我要给你一段代码。 但在此之前，一些一般性建议：
首先以很少的数据测试代码。 我的意思是，用10个字符的输入和2的len进行测试是好的，用3K +字符的输入和100+的len做测试是疯狂的。您如何看待您的代码是好是坏？
将代码剪切成小函数。 并对这些功能进行一些“统一”测试。这样，如果发生故障，您将可以在没有调试器的情况下快速发现该错误。如果检索数据的功能起作用，但最终结果有误，那么构造解决方案时可能问题就出在这里。如果结果很复杂，但是文件的最终价值很低，那么可能是写函数出错了。等等
使用str *函数。 用len 2的字符串手动向左移动是可以的，但是使用115的字符串进行手动移动是疯狂的！您花了多少时间？
这是一段代码，它将字符串作为输入并执行您想要的操作。 由于数组可以有任何长度，因此数组的最后一个值为NULL。 这就像一个字符串：要知道len，您要搜索特殊值'\ 0'。在这里，它不是'\ 0'，而是NULL。
由于calloc将结果数组和字符串的结果很好，这是因为calloc隐式将所有数组指针指向NULL，并将所有字符串内容设置为\ 0。 这就是为什么strncpy不会失败。
// TODO Do the description
char** Magic(const char * const input, size_t len)
{
char **array = NULL;
size_t arraySize = 0;
size_t inputLen = strlen(input);
char **returnFunction = NULL;
// Basic check (assert ?)
if (!len) {
// TODO Error message
goto END_FUNCTION;
}
// Calcul of the array length
if (len <= inputLen) {
arraySize = inputLen - len + 1;
}
// Last array value must be NULL in order to know the array length
++arraySize;
if (!(array = calloc(arraySize, sizeof(*array)))) {
// TODO Error message
goto END_FUNCTION;
}
for (size_t i = 0; i < arraySize - 1; ++i) {
if (!(array[i] = calloc(len + 1, sizeof(*array[i])))) {
// TODO Error message
goto END_FUNCTION;
}
strncpy(array[i], input + i, len);
}
returnFunction = array;
array = NULL;
/* GOTO */END_FUNCTION:
if (array) {
for (size_t i = 0; i < arraySize; ++i) {
free(array[i]);
}
free(array);
}
return (returnFunction);
}
int main(void)
{
char *input = "ABCDEFGIHJ";
size_t inputLen = strlen(input);
char **result = NULL;
for (size_t len = 1; len <= inputLen; ++len) {
// Get result
if (!(result = Magic(input, len))) {
// TODO error log ?
continue;
}
// Display result
printf("result for %zu len : ", len);
for (size_t i = 0; result[i]; ++i) {
printf("%s%s", result[i], result[i + 1] ? ", " : "\n");
}
// Free result
for (size_t i = 0; result[i]; ++i) {
free(result[i]);
}
free(result);
result = NULL;
}
return (EXIT_SUCCESS);
}
剩下的就是：检索数据（然后在“ input”参数中使用它）并显示/写入数据。 对于这两项，执行功能。
然后测试。很多测试。 不要忘记检查调用函数时是否失败。
答案 1 :(得分：0)
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
int main(void)
{
char wmers[115];
int i = 1, j = 2;
FILE *input = NULL;
FILE *output;
if (!(input = fopen("exon11.txt", "r"))) {
// Error
return (EXIT_FAILURE);
}
if (!fgets(wmers,115,input)) {
// Error ?
}
printf(">%d\n%s\n\n",i,wmers);
i++;
output=fopen("2.txt", "w");
fputs(wmers,output);
for(int c = fgetc(input); c != EOF; c = fgetc(input))
{
wmers[0] = wmers[1];
wmers[1] = wmers[2];
wmers[2] = wmers[3];
wmers[3] = wmers[4];
wmers[4] = wmers[5];
wmers[5] = wmers[6];
wmers[6] = wmers[7];
wmers[7] = wmers[8];
wmers[8] = wmers[9];
wmers[9] = wmers[10];
wmers[10] = wmers[11];
wmers[11] = wmers[12];
wmers[12] = wmers[13];
wmers[13] = wmers[14];
wmers[14] = wmers[15];
wmers[15] = wmers[16];
wmers[16] = wmers[17];
wmers[17] = wmers[18];
wmers[18] = wmers[19];
wmers[19] = wmers[20];
wmers[20] = wmers[21];
wmers[21] = wmers[22];
wmers[22] = wmers[23];
wmers[23] = wmers[24];
wmers[24] = wmers[25];
wmers[25] = wmers[26];
wmers[26] = wmers[27];
wmers[27] = wmers[28];
wmers[28] = wmers[29];
wmers[29] = wmers[30];
wmers[30] = wmers[31];
wmers[31] = wmers[32];
wmers[32] = wmers[33];
wmers[33] = wmers[34];
wmers[34] = wmers[35];
wmers[35] = wmers[36];
wmers[36] = wmers[37];
wmers[37] = wmers[38];
wmers[38] = wmers[39];
wmers[39] = wmers[40];
wmers[40] = wmers[41];
wmers[41] = wmers[42];
wmers[42] = wmers[43];
wmers[43] = wmers[44];
wmers[44] = wmers[45];
wmers[45] = wmers[46];
wmers[46] = wmers[47];
wmers[47] = wmers[48];
wmers[48] = wmers[49];
wmers[49] = wmers[50];
wmers[50] = wmers[51];
wmers[51] = wmers[52];
wmers[52] = wmers[53];
wmers[53] = wmers[54];
wmers[54] = wmers[55];
wmers[55] = wmers[56];
wmers[56] = wmers[57];
wmers[57] = wmers[58];
wmers[58] = wmers[59];
wmers[59] = wmers[60];
wmers[60] = wmers[61];
wmers[61] = wmers[62];
wmers[62] = wmers[63];
wmers[63] = wmers[64];
wmers[64] = wmers[65];
wmers[65] = wmers[66];
wmers[66] = wmers[67];
wmers[67] = wmers[68];
wmers[68] = wmers[69];
wmers[69] = wmers[70];
wmers[70] = wmers[71];
wmers[71] = wmers[72];
wmers[72] = wmers[73];
wmers[73] = wmers[74];
wmers[74] = wmers[75];
wmers[75] = wmers[76];
wmers[76] = wmers[77];
wmers[77] = wmers[78];
wmers[78] = wmers[79];
wmers[79] = wmers[80];
wmers[80] = wmers[81];
wmers[81] = wmers[82];
wmers[82] = wmers[83];
wmers[83] = wmers[84];
wmers[84] = wmers[84];
wmers[85] = wmers[86];
wmers[86] = wmers[87];
wmers[87] = wmers[88];
wmers[88] = wmers[89];
wmers[89] = wmers[90];
wmers[90] = wmers[91];
wmers[91] = wmers[92];
wmers[92] = wmers[93];
wmers[93] = wmers[94];
wmers[94] = wmers[95];
wmers[95] = wmers[96];
wmers[96] = wmers[97];
wmers[97] = wmers[98];
wmers[98] = wmers[99];
wmers[99] = wmers[100];
wmers[100] = wmers[101];
wmers[101] = wmers[102];
wmers[102] = wmers[103];
wmers[103] = wmers[104];
wmers[104] = wmers[105];
wmers[105] = wmers[106];
wmers[106] = wmers[107];
wmers[107] = wmers[108];
wmers[108] = wmers[109];
wmers[109] = wmers[110];
wmers[110] = wmers[111];
wmers[111] = wmers[112];
wmers[112] = wmers[113];
wmers[113] = wmers[114];
wmers[114] = c;
printf(">%d\n%s\n\n",j,wmers);
j++;
fputs(wmers,output);
}
return (EXIT_SUCCESS);
}
这是exon11.txt的内容。
CTGCTTGTGAATTTTCTGAGACGGATGTAACAAATACTGAACATCATCAACCCAGTAATAATGATTTGAACACCACTGAGAAGCGTGCAGCTGAGAGGCATCCAGAAAAGTATCAGGGTAGTTCTGTTTCAAACTTGCATGTGGAGCCATGTGGCACAAATACTCATGCCAGCTCATTACAGCATGAGAACAGCAGTTTATTACTCACTAAAGACAGAATGAATGTAGAAAAGGCTGAATTCTGTAATAAAAGCAAACAGCCTGGCTTAGCAAGGAGCCAACATAACAGATGGGCTGGAAGTAAGGAAACATGTAATGATAGGCGGACTCCCAGCACAGAAAAAAAGGTAGATCTGAATGCTGATCCCCTGTGTGAGAGAAAAGAATGGAATAAGCAGAAACTGCCATGCTCAGAGAATCCTAGAGATACTGAAGATGTTCCTTGGATAACACTAAATAGCAGCATTCAGAAAGTTAATGAGTGGTTTTCCAGAAGTGATGAACTGTTAGGTTCTGATGACTCACATGATGGGGAGTCTGAATCAAATGCCAAAGTAGCTGATGTATTGGACGTTCTAAATGAGGTAGATGAATATTCTGGTTCTTCAGAGAAAATAGACTTACTGGCCAGTGATCCTCATGAGGCTTTAATATGTAAAAGTGAAAGAGTTCACTCCAAATCAGTAGAGAGTAATATTGAAGACAAAATATTTGGGAAAACCTATCGGAAGAAGGCAAGCCTCCCCAACTTAAGCCATGTAACTGAAAATCTAATTATAGGAGCATTTGTTACTGAGCCACAGATAATACAAGAGCGTCCCCTCACAAATAAATTAAAGCGTAAAAGGAGACCTACATCAGGCCTTCATCCTGAGGATTTTATCAAGAAAGCAGATTTGGCAGTTCAAAAGACTCCTGAAATGATAAATCAGGGAACTAACCAAACGGAGCAGAATGGTCAAGTGATGAATATTACTAATAGTGGTCATGAGAATAA AACAAAAGGTGATTCTATTCAGAATGAGAAAAATCCTAACCCAATAGAATCACTCGAAAAAGAATCTGCTTTCAAAACGAAAGCTGAACCTATAAGCAGCAGTATAAGCAATATGGAACTCGAATTAAATATCCACAATTCAAAAGCACCTAAAAAGAATAGGCTGAGGAGGAAGTCTTCTACCAGGCATATTCATGCGCTTGAACTAGTAGTCAGTAGAAATCTAAGCCCACCTAATTGTACTGAATTGCAAATTGATAGTTGTTCTAGCAGTGAAGAGATAAAGAAAAAAAAGTACAACCAAATGCCAGTCAGGCACAGCAGAAACCTACAACTCATGGAAGGTAAAGAACCTGCAACTGGAGCCAAGAAGAGTAACAAGCCAAATGAACAGACAAGTAAAAGACATGACAGCGATACTTTCCCAGAGCTGAAGTTAACAAATGCACCTGGTTCTTTTACTAAGTGTTCAAATACCAGTGAACTTAAAGAATTTGTCAATCCTAGCCTTCCAAGAGAAGAAAAAGAAGAGAAACTAGAAACAGTTAAAGTGTCTAATAATGCTGAAGACCCCAAAGATCTCATGTTAAGTGGAGAAAGGGTTTTGCAAACTGAAAGATCTGTAGAGAGTAGCAGTATTTCATTGGTACCTGGTACTGATTATGGCACTCAGGAAAGTATCTCGTTACTGGAAGTTAGCACTCTAGGGAAGGCAAAAACAGAACCAAATAAATGTGTGAGTCAGTGTGCAGCATTTGAAAACCCCAAGGGACTAATTCATGGTTGTTCCAAAGATAATAGAAATGACACAGAAGGCTTTAAGTATCCATTGGGACATGAAGTTAACCACAGTCGGGAAACAAGCATAGAAATGGAAGAAAGTGAACTTGATGCTCAGTATTTGCAGAATACATTCAAGGTTTCAAAGCGCCAGTCATTTGCTCCGTTTTCAAATCCAGGAAATGCAGAAGAGGAATGTGCAACATTCTCTGCCCACTCT GGGTCCTTAAAGAAACAAAGTCCAAAAGTCACTTTTGAATGTGAACAAAAGGAAGAAAATCAAGGAAAGAATGAGTCTAATATCAAGCCTGTACAGACAGTTAATATCACTGCAGGCTTTCCTGTGGTTGGTCAGAAAGATAAGCCAGTTGATAATGCCAAATGTAGTATCAAAGGAGGCTCTAGGTTTTGTCTATCATCTCAGTTCAGAGGCAACGAAACTGGACTCATTACTCCAAATAAACATGGACTTTTACAAAACCCATATCGTATACCACCACTTTTTCCCATCAAGTCATTTGTTAAAACTAAATGTAAGAAAAATCTGCTAGAGGAAAACTTTGAGGAACATTCAATGTCACCTGAAAGAGAAATGGGAAATGAGAACATTCCAAGTACAGTGAGCACAATTAGCCGTAATAACATTAGAGAAAATGTTTTTAAAGAAGCCAGCTCAAGCAATATTAATGAAGTAGGTTCCAGTACTAATGAAGTGGGCTCCAGTATTAATGAAATAGGTTCCAGTGATGAAAACATTCAAGCAGAACTAGGTAGAAACAGAGGGCCAAAATTGAATGCTATGCTTAGATTAGGGGTTTTGCAACCTGAGGTCTATAAACAAAGTCTTCCTGGAAGTAATTGTAAGCATCCTGAAATAAAAAAGCAAGAATATGAAGAAGTAGTTCAGACTGTTAATACAGATTTCTCTCCATATCTGATTTCAGATAACTTAGAACAGCCTATGGGAAGTAGTCATGCATCTCAGGTTTGTTCTGAGACACCTGATGACCTGTTAGATGATGGTGAAATAAAGGAAGATACTAGTTTTGCTGAAAATGACATTAAGGAAAGTTCTGCTGTTTTTAGCAAAAGCGTCCAGAAAGGAGAGCTTAGCAGGAGTCCTAGCCCTTTCACCCATACACATTTGGCTCAGGGTTACCGAAGAGGGGCCAAGAAATTAGAGTCCTCAGAAGAGAACTTATCTAGTGAGGATGAAGAGC TTCCCTGCTTCCAACACTTGTTATTTGGTAAAGTAAACAATATACCTTCTCAGTCTACTAGGCATAGCACCGTTGCTACCGAGTGTCTGTCTAAGAACACAGAGGAGAATTTATTATCATTGAAGAATAGCTTAAATGACTGCAGTAACCAGGTAATATTGGCAAAGGCATCTCAGGAACATCACCTTAGTGAGGAAACAAAATGTTCTGCTAGCTTGTTTTCTTCACAGTGCAGTGAATTGGAAGACTTGACTGCAAATACAAACACCCAGGATCCTTTCTTGATTGGTTCTTCCAAACAAATGAGGCATCAGTCTGAAAGCCAGGGAGTTGGTCTGAGTGACAAGGAATTGGTTTCAGATGATGAAGAAAGAGGAACGGGCTTGGAAGAAAATAATCAAGAAGAGCAAAGCATGGATTCAAACTTAG