count的初始化和count++的位置很重要

/*** * 8.素数和 */int n = in.nextInt();int m = in.nextInt();int sum = 0;int count = 1;for (int i = 2; count <= m; i++){    boolean isPrime = true;    for(int j = 2; j < i; j++ ){        if (i % j == 0){            isPrime = false;            break;        }    }    if (isPrime){        if (count >= n){            sum += i;            System.out.print("和：i=" + sum);        }        count++;    }}System.out.println("素数n-m的和：" + sum);