举出c语言不按顺序执行的代码例子

以下是一个简单的C语言状态机示例，其中通过switch语句实现非顺序执行：

#include <stdio.h>

int main() {
    enum State {STATE_START, STATE_A, STATE_B, STATE_C, STATE_END};
    enum State currentState = STATE_START;
    int input;

    while (currentState != STATE_END) {
        switch (currentState) {
            case STATE_START:
                printf("Enter A to go to state A, B to go to state B, or C to go to state C: ");
                scanf(" %c", &input);
                if (input == 'A') {
                    currentState = STATE_A;
                } else if (input == 'B') {
                    currentState = STATE_B;
                } else if (input == 'C') {
                    currentState = STATE_C;
                }
                break;
            case STATE_A:
                printf("You are in state A. Enter any key to go back to the start state: ");
                scanf(" %c", &input);
                currentState = STATE_START;
                break;
            case STATE_B:
                printf("You are in state B. Enter any key to go back to the start state: ");
                scanf(" %c", &input);
                currentState = STATE_START;
                break;
            case STATE_C:
                printf("You are in state C. Enter any key to go back to the start state: ");
                scanf(" %c", &input);
                currentState = STATE_START;
                break;
        }
    }

    return 0;
}

在这个示例中，程序根据用户的输入进入不同的状态，而不是按照顺序执行。通过switch语句和枚举类型，状态机可以实现非顺序执行的功能。