leetCode(30) - Substring with Concatenation of All Words

Problem:

You are given a string, s, and a list of words, words, that are all of the same length. Find all starting indices of substring(s) in s that is a concatenation
of each word in wordsexactly once and without any intervening characters.

For example, given:
s: 

"barfoothefoobarman"

words: 

["foo", "bar"]

You should return the indices: 

[0,9]

.

(order does not matter).

Solution:

由于长度是固定的，因此固定每一个字符串开始的位置，然后向后搜索，查看每一个字符串是否存在，如果不存在i++

C语言源代码（260ms）：

sub不free的话会MLE

[cpp]
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typedef struct Node{  
    char* word;  
    int times;  
    struct Node* next;  
}data;  
#define SIZE 1000  
int hash(char* word){  
    int i=0,h=0;  
    for(;word[i];i++){  
        h=(h*31+word[i])%SIZE;  
    }  
    return h;  
}  
int InsertMap(data** map,char* word,int lenw){  
    int h = hash(word);  
    if(map[h]==NULL){  
        map[h]=(data*)malloc(sizeof(data));  
        map[h]->word=(char*)malloc(sizeof(char)*(lenw+1));  
        map[h]->times=1;  
        strcpy(map[h]->word,word);  
        map[h]->next=NULL;  
        return 1;  
    }else{  
        data* p=map[h];  
        while(p->next!=NULL){  
            if(strcmp(p->word,word)==0){  
                p->times++;  
                return p->times;  
            }  
            p=p->next;  
        }  
        if(strcmp(p->word,word)==0){  
            p->times++;  
            return p->times;  
        }else{  
            data* tmp=(data*)malloc(sizeof(data));  
            tmp->word=(char*)malloc(sizeof(char)*(lenw+1));  
            tmp->times=1;  
            strcpy(tmp->word,word);  
            tmp->next=NULL;  
            p->next=tmp;  
            return 1;  
        }  
    }  
}  
int FindMap(data** map,char* sub){  
    int h = hash(sub);  
    if(map[h]==NULL){  
        return -1;  
    }else{  
        data* p=map[h];  
        while(p!=NULL){  
            if(strcmp(p->word,sub)==0){  
                return p->times;  
            }  
            p=p->next;  
        }  
        return -1;  
    }  
}  
char* substring(char* s,int start,int len){  
    char* sub=(char*)malloc(sizeof(char)*(len+1));  
    int i=0;  
    for(;i<len;i++){  
        sub[i]=s[i+start];  
    }  
    sub[i]=0;  
    return sub;  
}  
int* findSubstring(char* s, char** words, int wordsSize, int* returnSize) {  
    int lenw=strlen(words[0]),lens=strlen(s),length=wordsSize;  
    int* res=(int*)malloc(sizeof(int)*(lens-lenw*length+1));  
    data** map=(data**)malloc(sizeof(data*)*SIZE);  
    data** tmp=(data**)malloc(sizeof(data*)*SIZE);  
    int i,j;  
    for(i=0;i<SIZE;i++){  
        map[i]=NULL;  
        tmp[i]=NULL;  
    }  
    for(i=0;i<length;i++){  
        InsertMap(map,words[i],lenw);  
    }  
    *returnSize=0;  
    for(i=0;i<lens-lenw*length+1;i++){  
        for(j=0;j<SIZE;j++){  
            if(tmp[j]!=NULL){  
                free(tmp[j]);  
                tmp[j]=NULL;  
            }  
        }  
        for(j=0;j<length;j++){  
            char* sub=substring(s,i+j*lenw,lenw);  
            int mapnum=FindMap(map,sub);  
            if(mapnum==-1)break;  
            int num=InsertMap(tmp,sub,lenw);  
            if(mapnum < num)break;  
            free(sub);  
        }  
        if(j>=length)res[(*returnSize)++]=i;  
    }  
    for(i=0;i<SIZE;i++)if(map[i]!=NULL)free(map[i]);  
    free(map);  
    return res;  
}  

C++源代码（704ms）：

[cpp]
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class Solution {  
public:  
    vector<int> findSubstring(string s, vector<string>& words) {  
        int lens=s.size(),lenw=words[0].size(),length=words.size();  
        map<string,int> strmap,tmp;  
        for(int i=0;i<length;i++){  
            strmap[words[i]]++;  
        }  
        vector<int> res;  
        for(int i=0;i<lens-lenw*length+1;i++){  
            tmp.clear();  
            int j=0;  
            for(j=0;j<length;j++){  
                string sub=s.substr(i+j*lenw,lenw);  
                if(strmap.find(sub) == strmap.end())break;  
                tmp[sub]++;  
                if(strmap[sub] < tmp[sub])break;  
            }  
            if(j>=length)res.push_back(i);  
        }  
        return res;  
    }  
};