【leetcode】不邻接植花

 

int cmp(const void* a, const void* b){
    return (*(int**)a)[0] > (*(int**)b)[0];
}

int* gardenNoAdj(int N, int** paths, int pathsSize, int* pathsColSize, int* returnSize){
    int i,j,k,temp,pst,cnt=2;
    for (i = 0; i < pathsSize; i++)
    {
        if (paths[i][0] < paths[i][1])
        {
            temp = paths[i][0];
            paths[i][0] = paths[i][1];
            paths[i][1] = temp;
        }
    }
    qsort(paths, pathsSize, sizeof(int*), cmp);
    int* arr = (int*)malloc(N * sizeof(int));
    for (i = 0; i < N; i++)
        arr[i] = 1;
    
    for (i = 0; i < pathsSize;)
    {
        if (paths[i][0] != cnt)
        {
            arr[cnt - 1] = 1;
        }
        else
        {
            int t[] = { 0, 1, 2, 3, 4 };
            pst = 0;
            while (i < pathsSize && paths[i][0] == cnt && pst<3){
                if (t[arr[paths[i][1] - 1]]){
                    t[arr[paths[i][1] - 1]] = 0;
                    pst++;
                }
                i++;
            }
            for (j = 1; j  < 5; j ++)
            {
                if (t[j]) {
                    arr[cnt - 1] = t[j];
                    break;
                }
            }        
        }
        cnt++;
    }
    *returnSize = N;
    return arr;
}

 

struct node {
    int paths[4];
    int path_num;
    int color;
};


int* gardenNoAdj(int N, int** paths, int pathsSize, int* pathsColSize, int* returnSize){

    if (N == 0) {
        *returnSize = 0;
        return NULL;
    }
    int *res = (int *)malloc(sizeof(int) * N);
    memset(res, 0, sizeof(int) * N);

    struct node *Nodes = (struct node *)malloc(sizeof(struct node) * N);
    memset(Nodes, 0, sizeof(struct node) * N);

    /* 构造邻接矩阵 */
    for(int i = 0; i < pathsSize; i++) {
        int start = paths[i][0] - 1;
        int end = paths[i][1] - 1;
        Nodes[start].paths[Nodes[start].path_num] = end;
        Nodes[start].path_num++;
        Nodes[end].paths[Nodes[end].path_num] = start;
        Nodes[end].path_num++;
    }

    /* 填充颜色 */
    for(int i = 0; i < N; i++) {
        int set[4] = {-1, -1, -1, -1};
        for(int path_i = 0; path_i < Nodes[i].path_num; path_i++) {
            int n_path = Nodes[i].paths[path_i];
            if (res[n_path] != 0) {         //这个颜色不能有
                set[res[n_path] - 1] = 0;
            }
        }
        for(int j = 0; j < 4; j++) {
            if (set[j] == -1) {
                res[i] = j + 1;
                break;
            }
        }
    }
    *returnSize = N;
    return res;
}