为啥以下代码原本是60分，把所有int数组类型改成float就ac了

#include <stdio.h>
int a[110][25];
float b[110];

int main (void) {
	int n, m;
	scanf("%d%d", &n, &m);
	for (int i = 0; i < n; i++) {
		int sum = 0;
		for (int j = 0; j < m; j++) {
			scanf("%d", &a[i][j]);
			sum += a[i][j];
		}
		int max = 0;
		int min = 10;
		for (int j = 0; j < m; j++) {
			if (a[i][j] > max)
				max = a[i][j];
			if (a[i][j] < min)
				min = a[i][j];
		}
		sum = sum - max - min;
		b[i] = sum / (m - 2)*1.0;
	}
	float ans = 0;
	for (int i = 0; i < n; i++)
		if (b[i] > ans)
			ans = b[i];
	printf("%.2f",ans)

	return 0;
}