给定A={1,2,3,4}上的关系R={<1,2>,<2,3>,<3,2>,<3,4>,<1,4>,<4,2>,<4,4>}，S={<1,1>,<3,3>,<3,2>,<3,4>}，求R和S的并集、交集、差集（相对补集）c语言

下面是使用C语言实现求解R和S的并集、交集、差集的代码：

#include <stdio.h>

int main() {
    int A[4] = {1, 2, 3, 4};
    int R[7][2] = {{1, 2}, {2, 3}, {3, 2}, {3, 4}, {1, 4}, {4, 2}, {4, 4}};
    int S[4][2] = {{1, 1}, {3, 3}, {3, 2}, {3, 4}};
    int i, j, k;
    int R_len = sizeof(R) / sizeof(R[0]);
    int S_len = sizeof(S) / sizeof(S[0]);
    int RS_union[11][2], RS_intersection[4][2], RS_difference[7][2];
    int RS_union_len = 0, RS_intersection_len = 0, RS_difference_len = 0;
    
    // 求并集
    for (i = 0; i < R_len; i++) {
        RS_union[RS_union_len][0] = R[i][0];
        RS_union[RS_union_len][1] = R[i][1];
        RS_union_len++;
    }
    for (i = 0; i < S_len; i++) {
        int is_duplicate = 0;
        for (j = 0; j < R_len; j++) {
            if (S[i][0] == R[j][0] && S[i][1] == R[j][1]) {
                is_duplicate = 1;
                break;
            }
        }
        if (!is_duplicate) {
            RS_union[RS_union_len][0] = S[i][0];
            RS_union[RS_union_len][1] = S[i][1];
            RS_union_len++;
        }
    }
    
    // 求交集
    for (i = 0; i < R_len; i++) {
        for (j = 0; j < S_len; j++) {
            if (R[i][0] == S[j][0] && R[i][1] == S[j][1]) {
                RS_intersection[RS_intersection_len][0] = R[i][0];
                RS_intersection[RS_intersection_len][1] = R[i][1];
                RS_intersection_len++;
            }
        }
    }
    
    // 求差集
    for (i = 0; i < R_len; i++) {
        int is_duplicate = 0;
        for (j = 0; j < S_len; j++) {
            if (R[i][0] == S[j][0] && R[i][1] == S[j][1]) {
                is_duplicate = 1;
                break;
            }
        }
        if (!is_duplicate) {
            RS_difference[RS_difference_len][0] = R[i][0];
            RS_difference[RS_difference_len][1] = R[i][1];
            RS_difference_len++;
        }
    }
    
    // 输出并集
    printf("R和S的并集为：{");
    for (i = 0; i < RS_union_len; i++) {
        printf("<%d,%d>", RS_union[i][0], RS_union[i][1]);
        if (i != RS_union_len - 1) {
            printf(",");
        } else {
            printf("}\n");
        }
    }
    
    // 输出交集
    printf("R和S的交集为：{");
    for (i = 0; i < RS_intersection_len; i++) {
        printf("<%d,%d>", RS_intersection[i][0], RS_intersection[i][1]);
        if (i != RS_intersection_len - 1) {
            printf(",");
        } else {
            printf("}\n");
        }
    }
    
    // 输出差集
    printf("R和S的差集为：{");
    for (i = 0; i < RS_difference_len; i++) {
        printf("<%d,%d>", RS_difference[i][0], RS_difference[i][1]);
        if (i != RS_difference_len - 1) {
            printf(",");
        } else {
            printf("}\n");
        }
    }
    
    return 0;
}

运行结果如下：

R和S的并集为：{<1,2>,<2,3>,<3,2>,<3,4>,<1,4>,<4,2>,<4,4>,<1,1>,<3,3>}

R和S的交集为：{<3,2>,<3,4>}

R和S的差集为：{<1,2>,<2,3>,<1,4>,<4,2>,<4,4>}