printf("1: %s\n", result ? "TRUE":"FALSE");

这段代码使用了三目运算符，如果result为真，则输出TRUE，否则输出FALSE。其中%s是格式化字符串，用于输出字符串类型的变量。三目运算符的语法为：condition ? value_if_true : value_if_false。如果condition为真，则返回value_if_true，否则返回value_if_false。下面是一个例子：

int result = 1;
printf("1: %s\n", result ? "TRUE":"FALSE"); // 输出：1: TRUE

result = 0;
printf("2: %s\n", result ? "TRUE":"FALSE"); // 输出：2: FALSE

相关问题

用c语言写一个输出关键路径 功能描述：根据创建的有向图及权重，调用TopologicalSort函数应用栈结构输出关键路径。 输出格式printf("Criticalpath: <%d,%d> length: %d\n", 开始节点数组index下标, 下一节点数组index下标, 权重);

好的，以下是用C语言编写输出关键路径的示例代码：

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

#define MAX_VERTEX_NUM 20
#define INFINITY 65535

typedef struct {
    int arc[MAX_VERTEX_NUM][MAX_VERTEX_NUM]; // 邻接矩阵
    int indegree[MAX_VERTEX_NUM]; // 入度
    int ve[MAX_VERTEX_NUM]; // 事件最早发生时间
    int vl[MAX_VERTEX_NUM]; // 事件最迟发生时间
    int path[MAX_VERTEX_NUM][MAX_VERTEX_NUM]; // 路径
    int vertex_num; // 顶点数
    int arc_num; // 弧数
} Graph;

typedef struct {
    int data[MAX_VERTEX_NUM];
    int top;
} Stack;

// 初始化栈
void InitStack(Stack *stack) {
    stack->top = -1;
}

// 判断栈是否为空
bool StackIsEmpty(Stack *stack) {
    return stack->top == -1;
}

// 判断栈是否已满
bool StackIsFull(Stack *stack) {
    return stack->top == MAX_VERTEX_NUM - 1;
}

// 入栈
void Push(Stack *stack, int data) {
    if (StackIsFull(stack)) {
        printf("Stack is full.\n");
        exit(1);
    }
    stack->data[++stack->top] = data;
}

// 出栈
int Pop(Stack *stack) {
    if (StackIsEmpty(stack)) {
        printf("Stack is empty.\n");
        exit(1);
    }
    return stack->data[stack->top--];
}

// 拓扑排序
bool TopologicalSort(Graph *graph, Stack *stack) {
    int i, j, k, count = 0;
    InitStack(stack);
    for (i = 0; i < graph->vertex_num; i++) {
        if (graph->indegree[i] == 0) {
            Push(stack, i);
        }
    }
    while (!StackIsEmpty(stack)) {
        j = Pop(stack);
        printf("%d ", j);
        count++;
        for (k = 0; k < graph->vertex_num; k++) {
            if (graph->arc[j][k] != INFINITY) {
                if (--graph->indegree[k] == 0) {
                    Push(stack, k);
                }
                if (graph->ve[j] + graph->arc[j][k] > graph->ve[k]) {
                    graph->ve[k] = graph->ve[j] + graph->arc[j][k];
                }
            }
        }
    }
    if (count < graph->vertex_num) {
        return false;
    } else {
        return true;
    }
}

// 关键路径
void CriticalPath(Graph *graph) {
    int i, j, k, e, l;
    Stack stack;
    bool result;
    result = TopologicalSort(graph, &stack);
    if (!result) {
        printf("The graph has a circle.\n");
        exit(1);
    }
    for (i = 0; i < graph->vertex_num; i++) {
        graph->vl[i] = graph->ve[graph->vertex_num - 1];
    }
    while (!StackIsEmpty(&stack)) {
        j = Pop(&stack);
        for (k = 0; k < graph->vertex_num; k++) {
            if (graph->arc[j][k] != INFINITY) {
                if (graph->vl[k] - graph->arc[j][k] < graph->vl[j]) {
                    graph->vl[j] = graph->vl[k] - graph->arc[j][k];
                }
            }
        }
    }
    for (i = 0; i < graph->vertex_num; i++) {
        for (j = 0; j < graph->vertex_num; j++) {
            graph->path[i][j] = -1;
        }
    }
    for (i = 0; i < graph->vertex_num; i++) {
        for (j = 0; j < graph->vertex_num; j++) {
            if (graph->arc[i][j] != INFINITY) {
                e = graph->ve[i];
                l = graph->vl[j] - graph->arc[i][j];
                if (e == l) {
                    printf("Criticalpath: <%d,%d> length: %d\n", i, j, graph->arc[i][j]);
                }
            }
        }
    }
}

int main() {
    Graph graph;
    int i, j, k, m, n, w;
    printf("Please input the vertex number and the arc number: ");
    scanf("%d %d", &graph.vertex_num, &graph.arc_num);
    for (i = 0; i < graph.vertex_num; i++) {
        for (j = 0; j < graph.vertex_num; j++) {
            graph.arc[i][j] = INFINITY;
        }
    }
    for (k = 0; k < graph.arc_num; k++) {
        printf("Please input the start vertex, the next vertex and the weight: ");
        scanf("%d %d %d", &m, &n, &w);
        graph.arc[m][n] = w;
        graph.indegree[n]++;
    }
    CriticalPath(&graph);
    return 0;
}

这个程序通过邻接矩阵来存储有向图，使用拓扑排序来求出每个事件的最早发生时间和最晚发生时间，然后求出关键路径。其中，INFINITY 表示两个顶点之间没有连边。

enum isBOOL{ isFalse=0, isTrue }; enum Choose { TcpHeartbeat=200, TcpExeCmd }; // 定义结构体 struct DataPacket { int sockfd; enum Choose choose; char cmdBuf[BUFFER_SIZE]; char returnValue[BUFFER_SIZE]; }; struct DataPacket datapacket; struct DataPacket receivePackets; int SetUpTCPtoSendInformation(char option[], char **command) { static int isFirstCall = 1; pthread_mutex_lock(&mutex); // 加锁 if (isFirstCall && strstr(option, "set")) { if (TCPCommand != NULL) { free(TCPCommand); } TCPCommand = malloc(strlen(*command) + 1); if (TCPCommand == NULL) { printf("Failed to set and obtain TCP command variable memory allocation\n"); goto fail; } strcpy(TCPCommand, *command); printf("set:%s\n", TCPCommand); isFirstCall = 0; goto succeed; } else if (!isFirstCall && strstr(option, "get") && TCPCommand != NULL && strlen(TCPCommand)) { free(*command); *command = malloc(strlen(TCPCommand) + 1); strcpy(*command, TCPCommand); printf("get:%s\n", *command); memset(TCPCommand, '\0', strlen(TCPCommand)); free(TCPCommand); TCPCommand = NULL; isFirstCall = 1; goto succeed; } memset(*command, 0, sizeof(*command)); strcpy(*command, ""); fail: pthread_mutex_unlock(&mutex); // 解锁 return 0; succeed: pthread_mutex_unlock(&mutex); // 解锁 return 1; } memset(&receivePackets, 0, sizeof(receivePackets)); int dataLen = recv(fd, &receivePackets, sizeof(receivePackets), 0); char *SendString = NULL; int result = SetUpTCPtoSendInformation("get", &SendString); if (result && SendString != NULL && strlen(SendString) > 0)详细代码

根据你提供的代码，我注意到你使用了一个名为 `datapacket` 的结构体来存储发送数据包的信息，并使用 `recv` 函数接收数据包。

在之后的代码中，你调用了 `SetUpTCPtoSendInformation("get", &SendString)` 来获取要发送的字符串。然后，你检查了 `SendString` 是否为 `NULL` 并且长度是否大于零。

这是一个合理的逻辑检查。如果条件满足，你可以使用 `SendString` 的值来执行发送操作。

请注意，你还需要在调用 `recv` 函数之前，使用 `memset` 函数将接收数据包的结构体 `receivePackets` 初始化为零，以确保接收到的数据正确填充到结构体中。

以下是修改后的代码示例：

enum isBOOL {
    isFalse = 0,
    isTrue
};

enum Choose {
    TcpHeartbeat = 200,
    TcpExeCmd
};

struct DataPacket {
    int sockfd;
    enum Choose choose;
    char cmdBuf[BUFFER_SIZE];
    char returnValue[BUFFER_SIZE];
};

struct DataPacket datapacket;
struct DataPacket receivePackets;

int SetUpTCPtoSendInformation(char option[], char **command) {
    static int isFirstCall = 1;
    pthread_mutex_lock(&mutex); // 加锁

    if (isFirstCall && strstr(option, "set")) {
        if (TCPCommand != NULL) {
            free(TCPCommand);
        }
        TCPCommand = malloc(strlen(*command) + 1);
        if (TCPCommand == NULL) {
            printf("Failed to set and obtain TCP command variable memory allocation\n");
            goto fail;
        }
        strcpy(TCPCommand, *command);
        printf("set:%s\n", TCPCommand);
        isFirstCall = 0;
        goto succeed;
    } else if (!isFirstCall && strstr(option, "get") && TCPCommand != NULL && strlen(TCPCommand)) {
        free(*command);
        *command = malloc(strlen(TCPCommand) + 1);
        strcpy(*command, TCPCommand);
        printf("get:%s\n", *command);
        memset(TCPCommand, '\0', strlen(TCPCommand));
        free(TCPCommand);
        TCPCommand = NULL;
        isFirstCall = 1;
        goto succeed;
    }

    memset(*command, 0, sizeof(*command));
    strcpy(*command, "");

fail:
    pthread_mutex_unlock(&mutex); // 解锁
    return 0;

succeed:
    pthread_mutex_unlock(&mutex); // 解锁
    return 1;
}

memset(&receivePackets, 0, sizeof(receivePackets)); // 初始化接收数据包的结构体

int dataLen = recv(fd, &receivePackets, sizeof(receivePackets), 0);

char *SendString = NULL;
int result = SetUpTCPtoSendInformation("get", &SendString);
if (result && SendString != NULL && strlen(SendString) > 0) {
    // 在这里执行发送 SendString 的操作
    printf("SendString: %s\n", SendString);
}

请确保你在使用 `SendString` 之前检查其是否为 `NULL`，以避免访问空指针错误。同时，根据你的实际需求，对发送操作进行相应的处理。