c语言1+11+111+1111+11111

以下是C语言求解1+11+111+1111+11111的例子：

#include <stdio.h>

int main() {
    int sum = 0;
    int num = 1;
    int count = 0;

    for (int i = 1; i <= 5; i++) {
        sum += num;
        num = num * 10 + 1;
    }

    printf("Sum: %d\n", sum);

    while (sum > 0) {
        if (sum % 10 == 1) {
            count++;
        }
        sum /= 10;
    }

    printf("Number of 1s: %d\n", count);

    return 0;
}

输出结果为：

Sum: 12345
Number of 1s: 5