17. 电话号码的字母组合c

/**
 * Note: The returned array must be malloced, assume caller calls free().
 */
char c[10][10]={" "," ","abc\0","def\0","ghi\0","jkl\0","mno\0","pqrs\0","tuv\0","wxyz\0"};
char temp[6];

void dfs(char** array,char* digits,int n,int* returnSize,int index){
    if(index>n) return ;
    if(index==n){
        array[*returnSize]=(char*)malloc(sizeof(char)*(n+1));
        for(int i=0;i<n;i++) array[*returnSize][i]=temp[i];
        array[*returnSize][n]=0;
        (*returnSize)++;
        return;
    }
    int t=digits[index]-'0';
    int i=0;
    while(c[t][i]!=0){
        temp[index]=c[t][i];
        dfs(array,digits,n,returnSize,index+1);
        temp[index]=0;
        i++;
    }
}

char** letterCombinations(char* digits, int* returnSize) { 
    for(int i=0;i<6;i++) temp[i]=0;
    int n=strlen(digits);
    *returnSize=0;
    if(digits[0]==0) return NULL;
    char** array=(char**)malloc(sizeof(char*)*3000);
    dfs(array,digits,n,returnSize,0);    
    return array;
}

字符串老是忘记最后加个0