47 lines
1 KiB
C
47 lines
1 KiB
C
const unsigned int MAX_N = 1000;
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unsigned int c_strlen(const char* s) {
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unsigned int i = 0;
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for (; *s; s++) i++;
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return i;
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}
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unsigned int less_than(const char *s1, const char* s2) {
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for(; *s1 == *s2 && *s1; s1++) s2++;
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return (*s1 < *s2);
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}
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void insertion_sort(const char* strs[], unsigned int n) {
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for (unsigned int i = 0; i < n-1; i++) {
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for (unsigned int j = i+1; j > 0; j--) {
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if (less_than(strs[j], strs[j-1])) {
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const char* tmp = strs[j-1];
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strs[j-1] = strs[j];
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strs[j] = tmp;
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} else {
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break;
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}
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}
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}
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}
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void sort_strings(const char* input, char* output, unsigned int n) {
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const char* strings[MAX_N];
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unsigned int i = 0;
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unsigned int offset = 0;
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for (i = 0; i < n; i++) {
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strings[i] = input + offset;
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offset += c_strlen(input + offset) + 1; // + 1 for NUL
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}
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insertion_sort(strings, n);
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offset = 0;
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for (i = 0; i < n; i++) {
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const unsigned int len = c_strlen(strings[i]);
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for (unsigned int j = 0; j <= len; j++) {
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output[offset + j] = strings[i][j];
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}
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offset += len + 1;
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}
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}
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