用c语言实现PageRank算法，要求读取一个文本文件，文本的每一行都记录了相连的两个网页的编号

下面是一个用C语言实现PageRank算法的代码，可以读取一个文本文件，文本的每一行都记录了相连的两个网页的编号，每个编号都从0开始：

#include <stdio.h>
#include <stdlib.h>
#include <math.h>

#define MAX_NODES 1000

int main(int argc, char **argv)
{
    if (argc != 2) {
        printf("Usage: %s <filename>\n", argv[0]);
        return 1;
    }

    char *filename = argv[1];
    FILE *fp = fopen(filename, "r");
    if (!fp) {
        printf("Error: cannot open file %s\n", filename);
        return 1;
    }

    // 读取文件，构建邻接矩阵
    int n = 0;
    int links[MAX_NODES][MAX_NODES] = {0};
    int from, to;
    while (fscanf(fp, "%d %d", &from, &to) == 2) {
        if (from >= MAX_NODES || to >= MAX_NODES) {
            printf("Error: node number exceeds maximum limit\n");
            return 1;
        }
        links[from][to] = 1;
        n = fmax(n, fmax(from, to) + 1);
    }
    fclose(fp);

    // 初始化PageRank值
    double PR[MAX_NODES];
    for (int i = 0; i < n; i++) {
        PR[i] = 1.0 / n;
    }

    // 迭代计算PageRank值
    double d = 0.85;
    int max_iter = 100;
    double tol = 1e-6;
    for (int iter = 0; iter < max_iter; iter++) {
        double new_PR[MAX_NODES] = {0};
        for (int i = 0; i < n; i++) {
            for (int j = 0; j < n; j++) {
                if (links[j][i]) {
                    new_PR[i] += PR[j] / links[j][0];
                }
            }
            new_PR[i] = (1 - d) / n + d * new_PR[i];
        }
        double max_diff = 0;
        for (int i = 0; i < n; i++) {
            max_diff = fmax(max_diff, fabs(new_PR[i] - PR[i]));
            PR[i] = new_PR[i];
        }
        if (max_diff < tol) {
            break;
        }
    }

    // 输出排序结果
    int idx[MAX_NODES];
    for (int i = 0; i < n; i++) {
        idx[i] = i;
    }
    for (int i = 0; i < n-1; i++) {
        for (int j = i+1; j < n; j++) {
            if (PR[idx[i]] < PR[idx[j]]) {
                int temp = idx[i];
                idx[i] = idx[j];
                idx[j] = temp;
            }
        }
    }
    for (int i = 0; i < n; i++) {
        printf("%d: %f\n", idx[i], PR[idx[i]]);
    }

    return 0;
}

其中，filename为要读取的文件名，links为邻接矩阵，PR为PageRank值数组，d为阻尼系数，max_iter为最大迭代次数，tol为收敛精度。程序输出排序结果，即所有节点的编号按照其PageRank值从大到小排序的列表。