1.将给定字符组合后，按字典序排序输出，示例：
输入：a, b, c;
输出：abc，acb，bac，bca，cab，cba
2.将给定字符组合后，按字典序排序输出，示例：
输入：a, b, c;
输出：a，b，c，ab，ac，bc, abc
//Example 1
#include <stdio.h>
#include <string.h>
void combchar(char* str, int from, int to)
{
if(from >= to){
for (int i = 0; i <= to; ++i){
PRINT("%c", str[i]);
}
PRINT(" ");
return;
}
int j = 0;
for(int i = from; i <= to; i++){
char tmp = str[i];
for(j = i; j-1 >= from; --j){
str[j] = str[j-1];
}
str[j] = tmp;
combchar(str, from+1, to);
for(j = from; j+1 <= i; ++j){
str[j] = str[j+1];
}
str[j] = tmp;
if(from == 0) PRINT("\n");
}
}
int main(){
char str[] = {'a', 'b', 'c', 'd'};
combchar(str, 0, sizeof(str)-1);
return 0;
}
Example 1 Result 结果如下所示：
Example 1 Result:
abcd abdc acbd acdb adbc adcb
bacd badc bcad bcda bdac bdca
cabd cadb cbad cbda cdab cdba
dabc dacb dbac dbca dcab dcba
//Example 2
#include <stdio.h>
#include <string.h>
#define PRINT printf
int num = 0;
void combination(char* str, int from, int to, int len, int t)
{
if(len == 1){
PRINT("%c\n", str[from]); ++num;
for(int j = from+1; j <= to; j++){
PRINT("%*c\n", 3*t+1, str[j]);
++num;
}
return;
}
for(int j = from; j <= to-len+1; j++){//1,2,3,4
PRINT("%*c->", (j==from) ? 1 : 3*t+1, str[j]);
combination(str, j+1, to, len-1, t+1);
}
}
void combination2(char* str, int from, int to, int len, int t, char* tmpStr)
{
if(len == 1){
for(int j = from; j <= to; j++){
tmpStr[t] = str[j];
for(int i = 0; i <= t; i++){
PRINT("%c", tmpStr[i]);
}
PRINT(" ");
}
}else{
for(int j = from; j <= to-len+1; j++){//1,2,3,4
tmpStr[t] = str[j];
combination2(str, j+1, to, len-1, t+1, tmpStr);
}
}
if(t == 0) PRINT("\n");
}
void findSubStr(char* str, int from, int to)
{
char tmpStr[from-to+1];
for(int j = 1; j <= to-from+1; j++){//len=1,2,3,4
//combination(str, from, to, j, 0);
combination2(str, j+1, to, len-1, t+1, tmpStr);
PRINT("-------------------%d|%d\n", j, num);
}
}
int main(){
char str[] = {'a', 'b', 'c', 'd'};
int size = strlen(str);
findSubStr(str, 0, size-1);
return 0;
}
Example 2 Result 结果如下所示：
Example 2 combination Result:
a
b
c
d
a->b
c
d
b->c
d
c->d
a->b->c
d
c->d
b->c->d
a->b->c->d
Example 2 combination2 Result
a b c d
ab ac ad bc bd cd
abc abd acd bcd
abcd
