541. 反转字符串 II C

void reverse_string(char* s,int head,int tail){
    while(head<=tail){
        char t=s[head];
        s[head]=s[tail];
        s[tail]=t;
        head++;
        tail--;
    }
}

char* reverseStr(char* s, int k) {
    int ssize=0;
    while(s[ssize]!=0) ssize++;
    for(int head=0;head<ssize;head+=2*k){
        if(ssize-head<=k){
            reverse_string(s,head,ssize-1);
        }else{
            reverse_string(s,head,head+k-1);
        }
    }
    return s;
}

结果：