leetcode刷题——多维枚举（一）

题目一：

思路：双指针

bool isSubsequence(char * s, char * t)
{
    int fast=0;
    int slow=0;
    while(slow<strlen(s)&&fast<strlen(t))
    {
        if(s[slow]==t[fast])
        {
            slow++;
        }
        fast++;
    }
    return slow==strlen(s);
}

题目二
思路："z"字搜索

bool searchMatrix(int** matrix, int matrixSize, int* matrixColSize, int target)
{
 if(target<matrix[0][0]||target>matrix[matrixSize-1][matrixColSize[0]-1])
    return false;
    int i=matrixSize-1;
    int j=0;
    while(i>=0&&j<=matrixColSize[0]-1)
    {
        if(matrix[i][j]==target)
            return true;
        else if(target<matrix[i][j])
            i--;
        else
            j++;
    }
    return false;

题目三

int numJewelsInStones(char * jewels, char * stones){
    int count = 0;
    for (int i = 0; i < strlen(jewels); i ++) 
    {
        for (int j = 0; j < strlen(stones); j ++) 
        {
            if (jewels[i] == stones[j]) 
            {
                count ++;
            }
        }
    }
    return count;
}